No problem Steve,
Having the CPU's multitasking will certainely help performance. Of course, the read/write would work best when reading from one drive while writing to a separate drive at the same time instead of from the same drive or partition.
Vista has improved Virtual Memory management. Although it usually works best when managed by Vista on the same partition as Vista is installed on, you can certainely relocate it to see if it will run better on the other drive. You can see how to do this in Vista here if needed.
Virtual Memory Paging File - Change
I think if you ran your programs off of the SATA drive and used the IDE drive for Virtual Memory and the temps (or the other way around), it may help some because of the read/write performance from above. The only drawback I see is having the IDE as a slave to the DVD drive. If you can, you might have the SATA connected to a SATA connector, then have the IDE drive and DVD drive on their own separate cable instead of slaved.
Just try each setup and see how it fast it feels to you under a heavy load.
Shawn