Gmail from Google is usually great, but it does have some bug-like features.
One of the most annoying is when your inbound mail is tagged with a label and should have been auto-archived, but is caught by their spam filter and placed in the spam folder.
Discovering and finding the mail in the spam folder is easy, but when you tell Gmail, that the mail isn’t spam, it doesn’t pop in to the archive (where the filter-rule should have put it). It pops back into the inbox, and you can then archive from there.
If they can figure out the mail ought to have been archived automatically, they should at least offer an easier way to run a filter on the inbox, than having to edit the filter and reapply it.