I think those are two different bugs, strength and stamina, both of which you can find in the bug tracker. The strength (and other boostable stats) one talked about here probably works as follows: You boots your strength (with potion or spell). This sets a timer, so that after some time the amount you increased, is subtracted again. If you log off (or crash) before that time and log in again, the system for some reason takes your normal stats, but then remembers it has not subtracted the boost, and so it does. So if you went from 100 to 112, you will end up with 88, if you went from 104 to 204, you will drop to 4 and drop everything you cannot carry.
Relogging in will restore the base stats again.
The bug may have something to do with that the system will only store the current stats to the database some minutes after you log off.