I have the same troubles as well... started like a week ago. Have tried all posted suggestions, no luck so far! :|

//CGA

>
> > Hmm...weird. It could be possible that some ISP's proxy cache holds an invalid
> > mamedats.zip....so this should get fixed within some time by itself.
>
> > It may happen that the automatic transfer mode has chosen 'text' instead of
> > 'binary' for the download and so the zip would be corrupt and the error
> appears.
>
> > I put an unzipped version of the xml online, try to use
> > "http://www.clrmame.com/clrmame.xml" for the url string. I've also reuploaded
> > the zip...maybe it works now ;)
>
> Tried to use the URL for the unzipped version same problem as before.
> I can download both the zipped and unzipped version by entering the URL in the
> browser without any problems. The XML in the zip file has today's date. So I
> would think that it is probably not a caching problem on the ISP's side.
> I really don't understand it.
>