After updating to multiprocessor version had definite computer slow-down.
It's back to 12.17 for me (a version that also works with outlook).
In addition, always thought that there was a definite advantage of a single-process browser. If things screw up, just shut it down and restart it. Multiple processes seem to multiply like rabbit droppings. Need to open task manager to clean them all up.
Anyone else feel the same?