VPN/PPTP timeout on MBP

I have a MacBookPro running 10.6.4.
Linksys WRT54GS router.
I set up a VPN/PPTP for connecting to my workplace from home.
The connection succeeds, but times out after 5 minutes.
Apple Care does not support VPN, but without it I can't use this computer from home.
Can someone help?

I figured it out. My VOIP router was causing the timeout.