Problems with logcheck.ignore rules

[hanasaki <hanasaki@hanaden.com>]

I have the following three rules in my logcheck.ignore file.
Originally, only the first rule was present but it does not seem to
ignore entries as the 2nd and 3rd do < Probably I need a lesson in regex
>.  Input would be appreciated.

PAM_unix.*: \(imap\) session [opened, closed] for .*
PAM_unix.*: \(imap\) session opened for .*
PAM_unix.*: \(imap\) session closed for .*

Thank you.