I used HFSLIP_60430a to generate a XP SP2 + WMP10 setup CD with all updates that Tomcat76 has got listed.
After finishing installing XP the system log says that there was a setup error and to look into setuperr.log in the windows dir.

The log says something like that the files drmclien.dll drmstor.dll are not correctly signed by microsoft.

Is this issue known or even already solved?

I wouldn't worry about this. SP2 has a similar problem with a DX9 file that doesn't contain a registry section even though the DX8 version of that file did. Windows setup still tries to register it even though it's not possible resulting in an error message being logged. I suppose your problem stems from Windows setup expecting the WMP9 versions of those two files.