Router pinging times out

I have a laptop connected to a wireless router ( Netgear ). The Internet connection ( 4MB
ADSL ) is somewhat choppy, i.e. it works flawlessly for one hour and then it suddenly
heavily slows down, only to come back after a minute or two. I tried pinging the router
and sometimes I get 3 or 4 "request timed out" messages, before the average time goes back
to a few milliseconds.
Any ideas as to what could be causing this malfunction ? Bad signal ? Malware ? I
regularly run Spybot and it finds some "red" trojans ( listed as "Firefox default"
though ).
Please help. Thanks.

Mike
Win XP, Intel PROSet card, Firefox browser, AVG antivirus, Spybot, AdAware, AVG
Antispyware

On Fri, 10 Nov 2006 15:16:15 +0300, Mike <(E-Mail Removed)> wrote:

> ...it works flawlessly for one hour and then it suddenly heavily slows
> down, only to come back after a minute or two.
> Any ideas as to what could be causing this malfunction ? Bad signal ?
May be it is just the radio interference. Does your WiFi manager report
the signal-to-noise ratio? What the reading is when the link works
normally - and what is shown during the slow-down period?

Tony.