Vista Wireless and 60 second lag/spike

[sifurlong]

I have been using my Philips streamium for over a year now without any problems.
Recently though I bought a new PC and a new laptop, both with Vista on.
Now I have a problem with the streamium, which is related to Vista, as it works fine using the XP machine on the same wireless setup.
It appears that there is a lag every 60 seconds (apparent when I am pinging my router) and that this is caused by Vista looking for a better wireless connection every 60 seconds. After a few minutes of streaming video or audio, the streamium then rebuffers and move onto the next file.
I am assuming that this is caused by the lag in the Wireless connection.

I have tried programs such as Vista anti lag etc but to no avail.
I know I can use the XP box, but that is due to be moved to my daughters room and dont want it on through the night as it is quite noisy. I also know that I can use a NAS drive with a UPnP server built in, but as of yet not in the position to buy one. Can anyone recommend a decent one??

Does anyone know a way to prevent the rescanning of the networks as it is driving me nuts?

Fingers crossed for some help.