the issue is permission of /wenphoto/cache.
lsphp5 need write thumbnails etc to this folder. at present apache can write to this folder but lsphp5 can't. this explains the issue.
set its permission and all sub folders' to 777, may resolve the issue.
so the suggestion:
1.turn safe mode off
2.chmod -R 777 wenphoto/cache
the rewrite rule should be ok, no need change.