The first of your problems, seems indeed weird, and I\'ve never before heard of anyone experiencing it. Perhaps there\'s something wrong on your end, but if, as you say, it only happens inside the sewer\'s I\'d recommend you not going there, at least till the next update is performed (soon now) and you can try again. Don\'t worry, there\'s lot of life outside them.
As for the second issue, it\'s well known. You can have some workarounds, one of them is using the fullbright feature (just search for fullbright in the forums, since there are lots of threads explaining how to do it) or you can download a relighted Ojaveda map that Ligh made, and that can be of help for you. Just look here:
http://www.planeshift3d.com/wbboard/thread.php?threadid=20543&boardid=33
