Since getting fully updated yeaterday to Avast 4.2 I am getting constant timeout messages that read
Internet connection timeout elapsed, continue waiting?
Ypager.exe==>cs41.msg.dcn.yahoo.com:25
Avast 4.6.603 is the latest 
Have you allowes ashwebsv.exe allowed in your firewall?
(as explained in many threads here)
And port 25 is normally used for SMTP (mail)
Before we can give more (better) help you need to tell us more.
Like:
What OS?
What exact version of Avast? (version nr is like x.x.xxx)
When does the problem happen?
What have you done sofar to try to solve the problem?
etc etc.
The mail scanner needs to be configured to ignore that program - insert this line to file avast4.ini under [MailScanner]:
IgnoreProcess=Ypager.exe