PC block

My pc blocks the first time I try to connect to Internet. This block lasts for 4-5 minutes then it works fine. During the block no apps start, as if a program uses all CPU or all memory. After the block all works fine.
I am almost sure that it was not caused by malware/virus/spyware/dialer/etc. as I used many program to remove all (Adaware, Spybot, Trend Micro Antyspyware, Ewido, CCleaner,fixing with Hijack,..etc and Norton AV 2006).

From task manager I suspect that the block is caused by the processes named Lucallbackproxy.exe which I think to belong to Norton Live Update system (5 or 6 of them appears in task manager immediately after the block stops). Is it probable that they can cause the block ? Should I disable automatic live update ?

Thanks

 

Errr..... Yes. Then at least you will know whether or not it is that causing the problem.

 

Ok the problem is not due to Norton 2006 because I've uninstalled it and the same problem appears.

It is strange because the block lasts only 4-5 minutes and no longer appears (until next reboot, of course) and it happens only for the first Internet connection (if I disconnect then I reconnect block never rehappens). It seems to me that it is a time-dependent error.

What can cause the total freeze of the system at connection ?

 

Do you have a firewall running? If you do what happens if you disable it do you connect proerly then?