Notebook won't select range expander

I have a notebook with a Linksys WPC 54G adaptor installed. my WAP is a Linksys WRT54G is in the other end of the house and I'm getting a weak signal on the notebook. SO I installed a Linksys WRE54G range expander. The notebook's adaptor sees them both, and shows the extender as a much stronger signal. I use the adaptor utilty to select the extender but it goes right back to the weaker signal of the WAP. How can I get notebook adaptor to stay with the stronger signal range expander??