I prefer mediawiki, except for its resource usage. IMO, it is the easiest to work with. Though i don't know if anyone that can, is willing to host it atm.
As for the sourceforge.net issue, I believe its because the webserver runs as only one user. Though its better than nothing, I think trying to fix the current wiki is a better solution.
IMHO switching to something like mediawiki or twiki would be a better option than trying to fix the existing wiki. But the main things that need fixing in the current wiki IMO are:
-The user interface is not very usable, and IMHO is rather ugly (not colors and such, but the whole layout of everything) -There's no sort of revision tracking in sight, which IMO is essencial for any sort of wiki -It's markup is rather strange and not easy to use
IMHO, these issues are much easier to solve by useing a different wiki than by trying to 'fix' the existing one.
If nobody here is willing to host a wiki, I think an ideal option would be Wikicities, which is a free wiki hosting service using mediawiki. For a good example of what a wiki on it looks like: here
wikicities may well be a better idea than running an another unusable zope-like wiki.
I don't know if the text-ads will bother anyone though, also there does seem to be a large proportion of irritiating 13 year-olds (to the extent that there is even a runescape wiki there already)
Perhaps the CF wiki can be repurposed if some people would join together.
I'm willing to work or attempt to fix the existing wiki, but only if three other people commit to that.
I'm not one to do all the work by myself, and then have it trrampled.
Its either you switch wikis, or a group project is done to try to salvage the existing one.