BTW, when I was talking about nudge values earlier, I forgot to mention that the nudge value is expressed in the value of the counter display, that is, in either minutes:seconds or bar|beat. So the same rule applies just with different values. The smallest default nudge value in bar|beats is 60 ticks. Pressing Command-Option-plus on the num pad will cycle it up to 120 ticks, then 240, 480, 1 beat, 2 beats and then a bar. Again, you can enter a custom value but will lose the ability to cycle on the fly unless you go back to one of the default values like 1 bar or 120 ticks, etc.
Slau