Oh, lordy. I keep discovering new problems with 2.2 that I did not realize I had. At first I thought the upgrade went smoothly. First I noticed 2.2 breaks the old wp-list-cats and wp-list-links, which messed up my Sidebar. I replaced with the new codes (not fun, waste of time). Then I noticed my Admin pages go Blank after I hit "Publish" or "Edit" or "Edit Comment" or edit the theme in Theme Editor. Then I noticed my RSS feed is broken. I have open threads about those later 2 problems, here on the forums.
I might be dumb. I suck at code. But I have used WP for 2 years, have learned a lot about CSS, PHP, MySQL, etc. And I have Never had this many problems with WP before.
Presently I am trying to learn how to rollback to 2.0.x.
Based on my personal experience, I would advise avoiding 2.2 like the plague (possibly 2.1 also, which I skipped). Then again, some people like it and have no problems. I am thankful WP is constantly working on Upgrades, but 2.2 has been a disaster for my site.
I changed hosts when I upgraded also, like you did. The reason I changed was to get the newer MySQL version required for the newer WP. I know that a different host, could have different default file Permissions, so I guess that might be the problem for you.
Good luck & keep us posted.