the problem exists in the user interface when sorting messages in any folder by "From." after sorting the mail in a folder by "From," and then clicking on an individual email to view it, it returns this error in the url:
msgs_pos=Unknown Tag: 'msgs_pos'

the link works and the email loads, but this error results in problems with the "previous" and "next" links

sorting the mail by any other attribute (date/subject/etc) returns a correct assignment to the msgs_pos variable.

this problems appears to exist in both gmail 2.2.0 and 2.2.1

any ideas?

That seems to be a bigger problem than it seems. The From field is actually partially sorted in code, so even with the msgs_pos problem being fixed, the next/prev links will not be entirely correct. I'll have to get back to you on a proper fix.

Adrian