Wireless signal level, Ver. 9.10

Just installed a side by side install of Ubuntu 9.10 with Windows XP. Everything has been great so far except fo a quirky wireless issue. I am using a Atmel chipset AT76C503/AT76C505 based USB device (Belkin F5D6050), the original driver shipped would not work, followed the directions here http://ubuntuforums.org/showthread.php?p=8042683 and was able to get it functioning.

The oddball problem is when I'm booted into Windows both the OS and iSSIDer show a maxed out signal level to the AP about -30dBm and or full bars in the graph of both. OK, so when I launch "Karmic" I am able to connect sometimes, when connected signal levels show anywhere from 2% to 5% or maybe a little higher. There is also alot of fluctuation in the levels???

What am I missing here? Is this something in the USB radio that is controlled by the driver I am using now or something in Ubuntu?? Not sure where to turn next at this point. Any help would be appreciated. I can provide any info needed just let me know. THANKS!