Optimizing Parallels

Hello all. I recently purchased Parallels v. 4 that I have running on a new 2.53Ghz Macbook Pro.

Here is my problem...

I have a high volume production grade Fujitsu scanner that unfortunately (software) is Windows Based. Prior to Parallels, I had was using the scanner in Windows via Bootcamp which was working fine (getting approx. 70-90 ppm scanning). However, once I try scanning under Parallels, the scanning speed drops dramatically down to about 20-30 ppm. I know that that the scanning software is pretty CPU intensive since it automatically crops, rotates and enhances but I am confused why there is such an enormous difference considering that Parallels v. 4 is supposed to recognize and use some of the available hardware acceleration that is in my computer. FYI, I have gone through the knowledge-base and adjusted all of the settings in Parallels to run at it's peak.

Anyone have any ideas?

Thanks!