gloom wrote:
So GRG is claiming that his mechanical rights have been infringed? ..and Tempest had his intellectual rights infringed? Because Tempest made the melody, but GRG made the "recording"? Please fill us in, if possible

If the records of the filing could be turned into an Internet Friendly Version(tm) -- for example a link to a law-archive that keeps records of these things, or perhaps a photocopy of the filing, that would be of great help.
{please include this warning if you copy/paste this to other forums: the below may be wrong, either in detail or in full, since I haven't seen the filing. Therefore, if anyone wants to get upset about anything... WAIT FOR THE ACTUAL FILING, and base your grievance on that! At some point I'm due to get the English translation of the filing, and then (with their permission),I'll either link to it or publish it.}
It's my understanding that the filing contests that GRG has been infringed, and that his work is sufficiently different to Tempest's as to qualify for copyright protection on its own merits. Note that I don't think this stops Tempest taking his own legal action, and it's not GRG claiming that he wrote Acidjazzed Evening: it's GRG claiming that what Timbaland stole from him was protected by copyright law by virtue of possessing creative attributes attributable to GRG himself. It's just a necessary prerequisite to establish that GRG's version was a product of skill and creativity rather than being a straight port that anyone could do, so you can then establish that it was legally possible for him to be infringed.
It's my own personal theory that Timbaland's steal had nothing to do with the original MOD, and that one of his lackeys is a SID fan, who just happened to use GRG's work. My belief is therefore that GRG's version of the track was instrumental (if you'll forgive the pun) in the composition of the piece.
Again, all disclaimers, I am not a lawyer, etc, etc, etc. Interpret with caution!
Chris