[unsolved] weird midi problem

[jerry_nomad]

Hi guys

Please accept my apologies if this has been covered before, I just couldn't figure out what to even search for regarding this issue

Just to kick things off, I bought my TI desktop about 2 years ago and it has been working without a hitch once I got it configured. Running 3 usb outs and 3 analog outs and not a single issue.

However after one of the updates (not sure which one) a weird thing started happening.
Basically imagine you have 2 midi notes say 1/4 bar length each right next to each other. The sustain on the amp envelope is cranked up all the way with the attack all the way down.
The problem is that instead of the note transition going smoothly, it sounds like there is a pause between notes??
Usually the problem goes away after restarting cubase (v5.5.1), but here's the really weird thing: the problem comes back as soon as I display virus control or open the midi part in the piano roll.

Has anyone else encountered this before?

I have checked just about everything, updated all the drivers, even reformatted my pc (running windows7 x64) and reinstalled everything again, the problem is still there.

Please help cos this is driving me up the wall