If you put up a test site and give me admin rights including ftp I will take a look at it.
I am considering making my own gallery for Joomla. I may start on it when Joomla 1.5 stabilizes.
If you are using SMF then it is possible to integrate Coppermine into Joomla. The SEF urls aren't as pretty though. I have done it but Coppermine didn't work well with SEF. I think Coppermine is way better there just aren't any great bridges for it.
That is correct. I can't test rc4 because it is too large. My hosting service doesn't allow large transfers and there's no way to change it except to install your own custom version of PHP. I'm really not keen on doing that just to install zOOm. Looks like OpenSEF and/or zOOm Gallery are dead projects anyway.
In the subject you say it sef_ext.php that is broken but in the body you say it's sef.rewriter.php that you changed? Sef.rewriter.php is not my code, only sef_ext.php. I don't think you should be changing sef.rewriter.php anyway. I imagine you just need to empty your trash or something.
This is still an active project. It appears that zOOm Gallery is dead and OpenSEF is dead so this project will die. If anyone has any legitimate bugs I will fix them if I can.