Hi, for the sake of testing i have completely uninstalled WMP10 (and its Windows Media Format 10 Runtime, security update patches, etc.), a procedure called "rollback". So i was back on WMP9. Starting WMP9 failed, so i downloaded WMP11beta2 and installed it.
When you start
Napster software it updates itself as expected. Then i downloaded an album and unDRMed it. The ibix version is:
11.0.5497.6285
In other words, updating my whole system to WMP11beta2 didnt harm the un'DRMing setup.