>Problem occurs when I do somwthing like:
>Main.prg
>? "before Worker Process"
>oMain.oWorker1.Process()
>? "after Worker Process"
>If Worker1.Process() takes two seconds to run Main.prg waits for that to complete before continuing.

Yep, this is NOT asynch calling...
>I can't call a new timer in Worker1 each time I want to run a method
>because there is an overhead of around 250ms before it fires.
Here you have to implement a busy/idle checking routine in your poolmanager
and have a continously checking timer in each of the workthreads.

20 ms is possible if the machine is not very busy, but for best switching
use DDE as mentioned before.

HTH

thomas