pane view problem

[[email protected]]

I have the following issue, installed the latest version of RC on a latest PHP 5.2 and httpd 2.0. the imap server in question is cyrus 2.2. Show preview pane is selected; if I select back and forth between emails in my 'Inbox', it may start out very fast (where I can immediately see each email in the preview pane after I click it), but then sometimes
there's a delay (maybe 5 seconds), and then if I select back and forth
several times, I get the long delay followed by the timeout error (and
dumped to the login screen)

This is in the logfiles around 5 times.
[21-Jan-2010 11:57:48 -0800]: IMAP Error: Authentication for eric failed (LOGIN): "+ PDE5MDkzOTQ2NDIuNTgxMjcyOUBsaXR0bGU+" (GET /mail/?_task=mail&_action=preview&_uid=266269&_mbox=INBOX&_framed=1)

first I was thinking it was my imap server, but each imapd is able to take 250 connections before it respawns an new imapd. Also no other imap client is broken this way. Thoughts?

[[email protected]]

here is theory

look at the error log:
[21-Jan-2010 11:57:48 -0800]: IMAP Error: Authentication for eric failed (LOGIN): "+ PDE5MDkzOTQ2NDIuNTgxMjcyOUBsaXR0bGU+" (GET /mail/?_task=mail&_action=preview&_uid=266269&_mbox=INBOX&_framed=1)
[21-Jan-2010 11:57:50 -0800]: IMAP Error: Authentication for eric failed (LOGIN): "+ PDEwMTkxMTM3NDAuNTgxMjczMUBsaXR0bGU+" (GET /mail/?_task=mail&_action=preview&_uid=266269&_mbox=INBOX&_framed=1)
[21-Jan-2010 11:57:53 -0800]: IMAP Error: Authentication for eric failed (LOGIN): "" (GET /mail/?_task=mail&_action=preview&_uid=266269&_mbox=INBOX&_framed=1)
[21-Jan-2010 11:57:54 -0800]: IMAP Error: Authentication for eric failed (LOGIN): "+ PDE1Mzk4NTI4MzEuNTgxMjczMEBsaXR0bGU+" (GET /mail/?_task=mail&_action=preview&_uid=266264&_mbox=INBOX&_framed=1)
[21-Jan-2010 11:57:54 -0800]: IMAP Error: Authentication for eric failed (LOGIN): "" (GET /mail/?_task=mail&_action=preview&_uid=266269&_mbox=INBOX&_framed=1)
[21-Jan-2010 11:57:56 -0800]: IMAP Error: Authentication for eric failed (LOGIN): "" (GET /mail/?_task=mail&_action=preview&_uid=266269&_mbox=INBOX&_framed=1)
[21-Jan-2010 12:11:00 -0800]: IMAP Error: Authentication for eric failed (LOGIN): "+ PDI2ODk1NzMzNTQuNTgxMzUyMkBsaXR0bGU+" (GET /mail/?_task=mail&_action=preview&_uid=266250&_mbox=INBOX&_framed=1)

each request has a diff hash for the authentication, could it be the case that RC is not matching the hash's to session properly?