Linksys Wireless pc Card signal loss

Hi all.
I'm having a signal strength loss/fluctuation with my Linksys wireless pci card pulling from my linksys router (both 802.11b)since i put it in my new rig. It was working fine b4 I took it out of my old rig and installed it. I updated the drivers from the website and put the rig in the exact spot the old one was..........everything else is exactly the same. I have a lappy rite next to the desktop using a wireless connection as well. The problem is the signal fluctuates anywhere from 1.0 mps to 11.0 mps.
when I look at the lappy the signal is a steady 11.0 mps. If i do a right click on the connection in the task bar and initiate a repair it brings it back up to 11.0 mps.But then, it will eventually start to fluctuate again.........weird! I'm wondering if it's a coincidence of timing and the card my be going bad(it's about 2.5yrs old) or there might be something I'm overlooking.
Is it time to upgrade to 802.11g?
Thoughts?