Older projects trouble in newer cubase (drops, glitches)

Hello, went from cubase 5 to 7, and was very happy with it until I started to discover tons of problems.

Mutes not functioning as normal. If I muted a channel in editor, there was always another channel randomly playing as well.
Random audio dropouts in wav-files. They did not happen because of spikes, just random drops. Strange.
Quite a big difference in performance. much worse

Here are my conclusions that might help some of you.
I do not have these problems when I create new project in cubase 7.5, only when loading older projects made in older cubase versions. So, my conclusion is that it does not really work with older projects.
You might have to recreate the older project. Convert instrument/midi tracks to wav. Don’t use freeze in older versions. Unfreeze the instruments and convert them.

And, Asio Guard does not work well for me at all. It worsen the performance noticeably. Thankfully it works really fine without it. I have an i7 core laptop (8 gig ram) running on “high performance” and it works way better than using any other steinberg settings or guards…

Why this is, beats me. But that is unfortunately the only solution I have so far, having searched quite a bit. A bummer Steinberg, but not too difficult recreating my projects though.

If anyone finds other solutions they are very welcome