Lenny annoyance

[David <wo9m-list@hughes.net>]

Ever since I upgraded from Etch to Lenny, I've been having problems.  My PC is 
a Toshiba Satellite 1805-S274 with a Netgear PCMCIA wifi card (Atheros 
chipset).  I'm using a stock kernel (2.6.26-2-686).  My desktop is Xfce, 
although I've tried Gnome and KDE as well.  On a regular basis, my system 
hangs for a few seconds.  During this period, I can move the mouse pointer 
but that is all.  It does not respond to any mouse clicks.  Also, during this 
time the CPU load goes to zero (according to the System Load Monitor on the 
panel) and the Network load pulses about once a second.  After a few seconds, 
the problem clears and everything goes back to normal.  Also, when I open 
Skype, the network connection crashes immediately, every time.  

I have googled the subject but found nothing about momentary hangs that 
recover.  What is the best way to troubleshoot such problems?  Or is anyone 
familiar with such problems?  Let me know if there's any more information I 
can provide that would help narrow down the problem.

Thanks, 

David