MM9 starting up extremely slow

I have an issue with MM9 starting up extremely slow. I have a system with an i7 processor and an SSD and "normal" programs start within seconds (even big MS Office Apps), but MM9 easily takes 30-60 seconds to startup!

Strange enough, it's always the first startup that day (or after reboot?) that takes that long. Subsequent program starts take more like 15 seconds, not 30+. But still too long, IMHO.

I have disabled all some "network related" options (no Design Partner participation, no update check, no login to Catalyst). I also disabled all plugins.

Any ideas, what else could take that long?

This is on Window 8 Pro using MM Pro 9 (v9.2.504) and I have only Windows Defender running, no other AV SW.