2
Don't upgrade to 2.2 at this moment, I would say. I tried, several times, several sites. Didn't work. WSOD's, database errors, had to use a backup to get my site back online. What ever the problem is, it looks like the release of 2.2 is too early. It seems to me that there is a lot of pressure to get the next versions of XOOPS out. That is absolutely NOT necessary. XOOPS already is an outstanding CMS. Don't spoil that by releasing semi-stable versions.