I am using ndiswrapper-0.8, sorry I should have said. I take it that you mean 2.6.10 and not 2.6.20 ?
-- Kim Lux, Diesel Research Inc.
The latest version of ndiswrapper seems to fix the problem with the 2.6.10 kernel, so you probably need to upgrade to get it to work (i was previously using ndiswrapper 0.8 and encountered the same problem).