I think Dan is on it. Linux does not like spaces in directory names. His method will bypass this issue and allow the directory to be read properly, not looked at as a command. The space makes Linux think that this is a command.
I have a wifi card (D-Link) installed on my system. The madwifi works fine in one distro (CVS version) and ndiswrapper in another (from source).
Dan, don't you have a Linksys in one of your systems? I may need help with this, as I just purchased one (WMP54G).