After recent update to the latest PC suite for P1i I encountered a CDC Comms interface problem.
The problem comes CDC Comms Interface that does not install properly. There are no drivers found on the CD that ships with the P1i.
No matter how many times Uninstalled/ Installed the software and the one from SE Web Site, Disabled Firewall etc - CDC Comms Interface drivers will not load. Even if you do driver update from Device Manager it does not find any on the Soft CD.
I solved it by re-installing PC Suite, but FIRST I removed the anti-virus and MS ActiveSync.
However, one thing you should try first above all: when you re-install, make sure that when asked for the new driver (which is not on the CD), you will allow the computer to connect to the internet to find the driver. I have the impression that SE just this week put the drivers in the correct place.
This way your installation may go well automatically, without having to remove additional software like anti virus etc.