After I changed the webmaster's password this afternoon, XOOPS 2.3 stopped letting me in. When I use the webmaster's user name "admin" and new password login, it says "Thanks for logging in, admin". However, it does NOT let me get into the system. Instead, original login page was shown. The same problem happened when I tried to login using normal registered user account. In addition, new users cannot get registered. Any ideas?

i think the new registration problem has been fixed in svn..

for a quick fix see this thread
https://xoops.org/modules/newbb/viewtopic.php?topic_id=65917&forum=2&post_id=296837#forumpost296837

It seems that after I cleared the private data via Firefox preferences, then it works. I am not sure exactly why. BTW, I am using Utuntu 8.04 and Firefox 3.0.2.