It doesn’t seem like such simple plugin would need any upgrade, but it had some issues, for which I apologize.
Now all the bugs with mono/stereo channels are gone.
Additionally, Comb Filter will not change it’s frequency with sampling rate. Sampling rates up to 192 KHz are supported in full range, at frequency 1 Hz. However, if you set higher frequency, sampling rate can be rised proportionally – there is no limit that could be reached in practical situation that I know of.
Download link is updated. Get it here.