I'm having the same issues. I was able to get the US feed to work fine but UK and DE throw bad header and attribute errors. I compared the php files and they are the same - so no clue why US works but UK and Germany do not. It would appear this contribution is no longer supported or updated which sucks - it's a much needed one.
I tried disabling the various attributes UK and DE base complained about by setting option "0" in the advanced configuration section. This worked but then I started seeing errors about "too many tabs" in header......
The google base application for uploading feeds is also broken and no longer functions.
I've decided to see if I can get the RSS feed contribution to work as a Google base feeder. Google base seems to support RSS and RSS 2.0 now, apparently.