Vista - Yahoo! Messenger and Home Network

Hi,
I have Windows Vista Home Premium SP1 x64.

After I installed Yahoo! Messenger 8.1 ( latest version ) sometimes after I
signing out, my computer internet connection is going down for some several
minutes:

-my prompt commander pinging is saying that no address has been found
-my taskbar icon is showing that i have internet connection
-i can't open a webpage
-i can't sign in in Live messenger or Yahoo! messenger
-i can download through uTorrent
Weird, right?
More weird is that in my house I have more PCs with Internet Connection, so,
we are linked to the internet through a ROUTER. I am the only who is having
wireless connection, others are linked throught cable, so everybody is having
the same problem as ME when this is happening to me...
If I power off my router and dsl modem and I power on the both of them,
after some minutes ( after their booting ) the internet problems are gone!


What can I do? What is this? Is my Yahoo! program guilty? Or not?
My router is having firewall ( for protection ), all the computer are having
antivirus and windows firewall activated ( all of them up to date ). No
viriis has been found on all the scanned computer. ( AVG Free Edition ) [
Firewall by Windows ]

*Yahoo! Messenger 9.0 i don't want to use because it is dezactivating me the
Windows Aero...

Please help me or open my mind about this problems!