Random Captcha dialog in Outlook 2003 with Hotmail Connector

A client has windows xp and office 2003.  They just bought a win7 laptop w/office 2010 and want to use outlook on it...and of course want email synced.  They currently have comcast.net email which does *not* support IMAP.  So I setup a live.com account for them, loaded up hotmail connector on both xp desktop and win7 laptop, and sync works amazingly well.

The problem is, on the xp machine (32-bit, outlook 2003), a CAPTCHA dialog pops up randomly when they send email.  I didn't anticipate this.

How do I make that CAPTCHA dialog stop popping up?

Thanks!