Have you set your cache sizes and preferences?.. also... have you set percentage of RAM for PS to use... this can have that kind of effect if it's set too low. Lou.

P.S. Have you set your pagefiles to "User managed" and set one for each partition?... if you have the HDD space, I recommend 2,000 for minimum and 4,000 for maximum one for each partition.

"..... and that was when things got interestiing."