Vista - All tcp-connections over wireless lost when unlocking computer

Hi,

Every time I unlock my computer either because the screensaver kicked-in or
because I locked it myself all my tcp-connections are lost over my wireless
connection. When I check the logs in the other end of the tcp-connections it
shows that the connections are lost exactly when I unlock the computer. For
example if I have a download ongoing, it will work fine during even if the
screensaver is there until I unlock it, then it is aborted and I have to
retry.

I have tried all hints I can find including disabling power saving, and all
"non-needed" protocols like ipv6 and link-layer stuff in the network
configurations.

I am going a lot back and fourth to my laptop so it is very disturbing that
I have to set up my vpns and restart all downloads every time I need to go to
a meeting.

All ideas of how to solve this would be great! I am running Vista on a Sony
Vaio VGN-SZ460N with the latest drivers available.

Thanks,

Andreas