Virus Ti - Filter cutoff won't track Portamento..?

[aitch]

Hi,

Recently bought a Virus Ti - amazing machine!!
I've become very familiar with structure and programming of the Ti, but can't get Filter Cutoff Freq to glide in sync with Oscillators when Portamento is applied. I've set 'Key Follow' to max in the Filter edit section, so the Freq is tracking perfectly, but jumps immediately from note to note while the Oscillators glide as Portamento value is increased. According to page 109 of the Virus Manual, Portamento should affect both Osc Freq and Filter Freq, but apparently this is not so.
It would be useful, for instance, to play pitched Noise by applying resonant filtering (with Key Follow) and using Portamento on the Filter Cutoff Freq.
Although the Matrix section is VERY versatile, there seems no way to get around this limitation. Any ideas anyone?
Perhaps a future firmware upgrade could address this...??

Thanks for listening!

Aitch