Machive + Kontakt crash in Cubase 7

I often use Kontakt in conjunction with Machfive 5 (3.1 version, 64 bits) in Cubase 7.
As soon as I load a huge program in Mach5, Cubase becomes unstable. Most of the time I cannot save the project. Even worse, I have to re-install MachFive from scratch.
Am I alone ? Any idea ?


Same problem once more, even after updating Cubase 7.0.6 : as soon as I use M5 with Kontakt, I get a weird behavior from the samples. My activity monitor has still 6GB memory usage left but the samples from Kontakt seem to “stutter”.

Then I get the following message from M5 :
<<MachFive 3 cannot run due to the following error:
This product cannot run because of problems communicating with a core component. Please reinstall the software, or download and run the driver installer located here:
If you still have problems after running these installers, please contact the software publisher for support.>>

And then, impossible to save my Cubase project :
<< The project could not be saved, because : an unexpected error occured. The system’s descrition is : Too many open files. No new project could be created.>>