On a new install of VTi with this machine i ran into severe problems with OsCam, this took me hours to figure out and involved uninstalling Oscam and reloading every version i could get my hands on, i also re-entered all my settings one by one from scratch and it didn't fix it.
The problem was OsCam was getting hammered with around decode and decrypt requests every second, i didn't have any recordings going and could not figure it out.
I eventually found the culprit, the machine has a feature called quick channel selection mode where it continues to demux and decrypt the last channels you have browsed, a) so you can zap back to them quickly? b) i think you can continue to timeshift the channels whilst zapping to another (They have this feature on TiVo).
Turn it off, it will absolutely batter your softcam with ecm requests.
It's a silly feature to have turned on by default and given VTi hides options away in the silliest of places it is very hard to find.