Hello Ulf,
now, after updating to Cubase 7.0.6, I cannot reproduce the problem anymore.
My Trial of Open Desk expired, but I now own the compressors and the EQ of the Yamaha Vintage Collection. With these Plug-Ins, I did experience the crashes consistently as soon as I would try to edit any Parameter. Now, no crashes anymore.
I am running Cubase 64 bit version, and I am using the 64 bit VST3 version of the plug-ins.
Regards, Mikael