Apparently Netstumbler doesn't work in Vista.

On my P5K Deluxe I just installed Realtek drivers (RTL8187_Vista_6.1281_WHQL_installshield.zip) which are older than the ones Windows Update finds, but the latest ones available on Realtek's website. These give the same spike issue.

Disabling rate adaptive mode and setting preamble mode to long does not help.

Unfortunately at my parent's house I do not have access to the router's configuration as currently my parent's are sharing with our neighbours. netsh shows that there is one other network operating on the same channel 6, both at similar signal strengths.

When I had a P5WDH I recall having the same problem even at my own apartment with a WRT54GS flashed to Tomato, full signal strength with the router 10 ft away. The P5WDH also has a Realtek wireless chipset. Is this a trend I am seeing?