I got the same problem at this moment :-(
dump file:
Microsoft (R) Windows Debugger Version 6.10.0003.233 X86
Copyright (c) Microsoft Corporation. All rights reserved.


Loading Dump File [E:\Programme\PlaneShift\PlaneShift_Jhaina Serefe_Version_Dec 25 2009_Addr004F5B65.dmp]
User Mini Dump File: Only registers, stack and portions of memory are available

Symbol search path is: *** Invalid ***
****************************************************************************
* Symbol loading may be unreliable without a symbol search path.           *
* Use .symfix to have the debugger choose a symbol path.                   *
* After setting your symbol path, use .reload to refresh symbol locations. *
****************************************************************************
Executable search path is:
Windows XP Version 2600 (Service Pack 3) MP (2 procs) Free x86 compatible
Product: WinNt, suite: SingleUserTS Personal
Machine Name:
Debug session time: Sun Jan  3 20:59:33.000 2010 (GMT+1)
System Uptime: not available
Process Uptime: 0 days 0:07:09.000
......................................................
This dump file has an exception of interest stored in it.
The stored exception information can be accessed via .ecxr.
(8d0.bc): Access violation - code c0000005 (first/second chance not available)
eax=ffffffff ebx=78552e73 ecx=141e1ea8 edx=00000600 esi=0012efee edi=000005fc
eip=7c91e4f4 esp=0012e4dc ebp=0012e4ec iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00000246
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for ntdll.dll -
ntdll!KiFastSystemCallRet:
7c91e4f4 c3              ret

Now I'll tell what happened, I hope this helpes:
First I started training a bit in the sewers and got killed by a npc (well it was too strong for me xD) so I died
In the death realm I moved towards it's end and stepped into this skull-face (the space in which doors are normally had this "no-frame"-effect which seem to occur often even in the city for example when I stepped in the library) I stepped through it and fell into nothingness. I saw in the chat window that it tried to reset my position because I would be out of bound. Next I tried the command /unstick which resetted my position to the plaza (btw background loading was on world) but I fell and saw this "no-frame"-effect. Furthermore, in the chat window there were several times "position out of bound, resetting position". I am not sure if I first logged off or first tried to use the /die command. I did both but I am not sure in which order. Nevertheless, loading the death realm I had the same problems and the client crashed the first time after several "out of bound"-messages. Relogging brought me back to the entrance of the death realm without "no-frame" adn without "out of bound"-spam. I walked the path along again and stepped again through this "no-frame"-skull face and got brought back to the plaza after falling and writing /unstick in the chat. 2 secs later the client crashed writing the dump file you see above... everytime I log in I see my character behind the blacksmith's hut and it seems as if it would crash everytime the client loads the modelfiles of other players. Unformentually, the client crashes now everytime  I log after ca. 2 secs.
VBOs are turned off and I tried to set "ThreadManager.AlwaysRunNow = true" in my psclient.cfg, too but it didn't help.

mh I hope this will help to fix it.
Ingame character name: Jhaina Serefe, operation system: windows xp sp3, latest drivers used
Please, fix it soon. And maybe you may add to the setup or in the char. selection screen a button to reset the char. position to the nearest town as long as this game runs under "beta" conditions in the next update.

Goodbye and farewell

Hi I recently trained a bit in the sewers and walked around suddenly I fell into nothingness because there was no floor bellow my character's feet. After falling a few seconds the client crashed with an "ACCESS_VIOLATION"-error. So, I tried to log in again but when I try to load the world the client crashes immediatly that means that I am unable to use the commands /unstick or /die or call a GM in-game. I can't tell you the excat position but maybe you can read it from the databse and reset it so I can play again. I hope you can help me thank you a lot.

Oh, and here is the content of the crash dump file (read with the WinDbg-tool):
Microsoft (R) Windows Debugger Version 6.10.0003.233 X86
Copyright (c) Microsoft Corporation. All rights reserved.


Loading Dump File [E:\Programme\PlaneShift\PlaneShift_Jhaina Serefe_Version_Dec 25 2009_Addr00516624.dmp]
User Mini Dump File: Only registers, stack and portions of memory are available

Symbol search path is: *** Invalid ***
****************************************************************************
* Symbol loading may be unreliable without a symbol search path.           *
* Use .symfix to have the debugger choose a symbol path.                   *
* After setting your symbol path, use .reload to refresh symbol locations. *
****************************************************************************
Executable search path is:
Windows XP Version 2600 (Service Pack 3) MP (2 procs) Free x86 compatible
Product: WinNt, suite: SingleUserTS Personal
Machine Name:
Debug session time: Sat Jan  2 20:40:07.000 2010 (GMT+1)
System Uptime: not available
Process Uptime: 0 days 0:05:05.000
......................................................
This dump file has an exception of interest stored in it.
The stored exception information can be accessed via .ecxr.
(6d8.cf8): Access violation - code c0000005 (first/second chance not available)
eax=ffffffff ebx=78552e73 ecx=1e541ea8 edx=00000540 esi=0012f1b6 edi=00000554
eip=7c91e4f4 esp=0012e6a4 ebp=0012e6b4 iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00000246
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for ntdll.dll -
ntdll!KiFastSystemCallRet:
7c91e4f4 c3              ret

Please reset my position and add a piece of floor to my position so that nobody else falls again  

EDIT: mh you may need my name xD My character is called Jhaina Serefe and I am using the newest client (v0.5.0) on windows xp sp3 with latest graphics drivers and a single-core cpu (oh yeah I know that's old^^)