Some people are having trouble seeing all of the new content. There could be a couple things going on that would cause this and several things you can try.
It can take 48 hours for your provider to point you towards the new server. You may be seeing mixed content from the new server and the old server if you came in through http:\\mosaic.spottedlop.net. This issue should resolve on its own. If it's Monday though, you might want to try some of the following things.
1. Make sure you are going straight to
http://www.mosaicminds.org/forums If you came in through the temporary URL things seem to get confused. If you are trying to log in and it doesn't take this is usually the problem.
2. Make sure your browser accepts cookies. MM sets a cookie that keeps you logged in for your session.
3. Clear your internet cache and close your browser, then restart. You may be seeing old copies of files that are stored on your computer. Here are instructions for clearing your browser cache.
How to Clear Your Browser's Cache
4.Clear your DNS cache. Your computer may be still pointing to the old site and need to get the new entry.
How to clear your DNS cache in Windows (also works for XP though site says Vista/Win 7
How to clear the DNS cache for Mac OS X