Interaction with PC Tools firewall

Since two days I’m experiencing long delays on connection.
I thought it was my ISP, then the network connections.
I’ve uninstalled PCTools firewall and everything seems normal.
Can anybody help me on troubleshotting the interaction between WebShield and PCTools?
Both PCTools and avast has been recently updated, but I think the problem is on the last PCTools version.

Avast 4.8.1169 (standard shield and webshield) and PC Tools Firewall 3.0.1.14 running fine on XP sp2 here.

Forget to say… Windows Vista 32 bits here.