I have a site that has been ranking very well in google for the past year (always top 4 for targetted phrases, often no 1) However, some time last week, it lost its site description from googles index and is now nowhere in the rankings. I am hoping this is a temporary glitch - the only thing that has changed last week is that my hosting provider has migrated to new machines. All my other sites seem fine, so I can't think this is the problem. The other pages in the site are still showing in the index, but don't have the BLs so aren't so highly rated.

Any ideas as to why/where it's gone and how to get it back? The latest BL update shows a significant increase in links (all of which I know have good anchor text) and also its PR is steady at 3.

Ideas welcome