That's a new one for me.
I happen to use Step Sequencer all day long, as I really like it for entering drum sequences. I am in the middle of creating all-midi versions of a bunch of Bill Bruford tunes, and have note-for-note transcriptions that I am using to put all the parts in.
I don't see this behavior in Step Sequencer.
Couple of questions for you - and also I will try some tests using SD 3 and will also post back on that, in case it in particular has some issues when used with Step Sequencer.
So,the questions:
1. Have you tried using Step Sequencer with any other synth? This would just be to try to determine if it is a global SD thing or not.
2. Do you have any latency issues just playing soft synths in general in Sonar?
3. Can you elaborate on the 'Fill Every' comment in your post? I am curious as to what you are asking it to do. This is so I can try to duplicate the effort and see what happens on my system.
4. Have you tried testing where you do a SEPARATE test of clicking on the little boxes, versus adding in the Fill Every thing that you are also doing? I just want to see if those two functions have some issue combined, versus behavior when used separately.
Sorry for all the questions. I have some time today, and would be quite willing to try to duplicate any tests per what you post back.
Bob Bone