v3 slows IM download badly

(:AGY)
A former user of v.2, I had to wait some time for v.3 and Vista compatibility before I could use CFP again.

I find it very thorough and decided to also incorporate BOClean in my defenses.

This morning when using Instant Messenger with a friend, he sent a pic file of about 250 Kb for me to view. Until he canceled I had spent some 7 mins waiting and the transfer had hardly reached the 1/3rd mark.

Judging by the signs of activity, it was CFP that was causing the slowdown.

Is this a known problem and is there a solution?

I had been using the PCTools free firewall and had no problems before with transfers in either direction.