I did get this error un-tarring the package. That's a delayed error from an earlier file in the package with "trailing garbage" (whatever that is). In my case, at least, the module still compiled and installed successfully.gzip: stdin: decompression OK, trailing garbage ignored
It doesn't inspire great confidence in the vendor's package, I know. But it seems to work.
For what it's worth, the hardware support pages indicate that the problem with the ethernet port has been resolved with UNR 9.10 (Karmic). I haven't tried it myself, yet.
I should probably have added that if you compile the driver, you'll have to re-compile with each kernel upgrade.