Ahh, I see the point of the ATTiny as a custom "make switching signal" IC. Shoot - it might even be a good way to make a base signal for my resolver-driver.
I do also like the point of keeping the high-frequency signals isolated.
In this case, I'm using much different code. The application is actually a dual H-bridge DC drive, ( mini electric snow cat ) and I only have one interrupt to provide timing for this signal and a blinky LED. The driver signal was, from what I could see on the 'scope, very stable, it just had that lag problem.
You've encouraged me to try some new stuff.
I'm going to get some inverters and see things work out with the ATTiny's as well.
Thanks for your help,
E*clipse