I've small problem too.
I tried to change project settings, changed latency, installed newest ASIO4ALL version.. Nothing helps. I don't have any problems with other Vienna Suite Plugins in FL Studio. Here some examples with hybrid and with convolution reverb.
(Win7 Ultimate x64 | 24GB RAM | i7 4 x 3.06)
By the way, I don't have this problems in cubase 6. Hybrid Reverb is realy great product! I would like to use it in FL Studio too (it's part of my workflow).
Thank you!