Having suffered a similar problem with my wife's laptop, I changed our system from the default channel 6 to 11. Since all has been fine. I suggest any channel as far away from the ones on the list should be OK.
I've been running on Ch 12 for a week or so and it seems a similar experience (regular interruptions) also my 2 laptops and mobile phone oh and the PS3 are all not now connecting to the net work since the change of channel...am I missing something, or should they all adapt without fuss?
I'm considering changing routers from the existing 3Com 3CRWE754G72 to a new all dancing Draytec here: click here
Is that a false move I wonder?
Ran a few speed tests last week and I seem to get 3.2 Mbps Download and 0.3/4 Upload. This sounds ok?
In some countries (but not the UK), the use of Channels 12 and 13 is not legal. Because of this, some Wireless Network Adapters are designed not to connect to these channels and this is almost certainly why you've been unable to connect. Try "11" which many routers use as the default channel.