jimbeetle - 5:24 pm on Feb 8, 2006 (gmt 0)

Sounds like you've done everything right on the server move. I do think you're digging a bit too deeply for the reason when this stands out:

Other than the one bit of new text to identify the new server everything else is identical.

It's sometimes surprising how simple changes to text can move a well-written page out of the sweet spot for a key phrase, but it does happen. If this is the only difference I'd change it back and wait to see what happens before investigating other, more intangible areas.