Scrub Performance

Just update from WXP - N5.5 to W7 - N7
most of update issue are solved except one.
the scrub performance is going down when video screen is active.
when using the same project in N5.5 on XP is the with or without video (the real analog scrubbing feel)
Now it’s poor skipping audio far of the analog feel.
Can this please be fixed in the next update?
Otherwise i’m thinking about downgrade back to N5.5

Finally a complete reinstall from scratch have solved the problem.
Strictly in order W7; update drivers; motherboard; video; enz. enz. reboots in between steps and monitoring CPU usage.
Takes 3(holy)day’s, but it works!