Web Filtering and Yahoo file transfer

I am unable to figure out why file transfers inside yahoo messenger client fail when the Web Filtering is on but does not fail when using MSN.

Have added anything that I can find int he logs relating to Yahoo to the exception list. Still have to shut the web filter off to get file transfer to not fail..

Using :
Model: ASG Software
License ID ******
Subscriptions: Base Functionality
Email Protection
Network Protection
Web Protection
Webserver Protection
Wireless Protection
Endpoint AntiVirus
Uptime: 1d 19h 58m

Current firmware version: 9.004-34
Your firmware is up to date.

Let me know if there is anything else that you need to help..

Thank You,