Latency Issues

Greetings,
I am using the Virus TI 2 with Sonar 8.5.3 (32bit and 64bit) and am having latency issues.

I'm running Win 7 x64
AMD 3.4gHz quad-core (AM3)
8GB RAM
Delta 44 Audio (PCI)

When I load the Virus in Sonar as a soft-synth using its USB audio, the latency on the Virus is fine but when loaded the latency on my other plugins is reduced quite a bit. My current project consists of 4 plugins (Konakt, Omisphere, Massive, Battery) and of course the Virus. My current sample buffer is 256 samples which has been perfect pre-Virus but when I load the virus, I can't seem to find that "magic" number. I've reduced the buffer as low as 64 samples but it kills my CPU utilization.

Any advice? I followed the recommended configuration in the setup guide but that didn't help any. Again the latency in the virus is fine but I need to find a way to get the same latency out of the other soft synths when the virus is loaded.

Thanks in advance,
Andrew

After reading a bit more on the forums...the "Live" button seems to do the trick though not what I'd call optimal. It'll do when I need to play a part on the other synths and will disable it when mixing down. It does seem to skew the timing on the Virus but only slightly.