Does PGP WDE slow down Parallels

I have Parallels running XP on my MBP 2.6 GHz with 4GB or RAM. Previously I had it working well, reading my Bootcamp partition, and switching between Mac and Windows was fast and flawless. I upgraded my HD and instead of Bootcamp just went with a straight Parallels install. This time switching between Mac and Windows is sluggish...jerky. And, running in Windows is slow. The only thing I can figure out is that I now use PGP whole disk encryption. It shouldn't make a difference, but is there evidence that PGP WDE slows Parallels down?

 

PGP WDE seems to slow down Parallels 5

I'm trying the same thing. I find that it takes 1:21 to resume my Windows 7 VM from an encrypted drive vs only 0:29 from a unencrypted drive. After it's resumed it takes 0:27 to open Windows Explorer vs only 0:03 when the VM is on a unencrypted drive. Oddly, PGP WDE doesn't seem to effect other Mac programs.

I ran Xbench both with PGP WDE and without. I think the Disk test tells the tale - disk i/o is considerably slower and I suspect that Parallels make heavier use of the disk than most Mac programs.

Without WDE:
Disk Test 48.38
Sequential 72.90
Uncached Write 105.94 65.04 MB/sec [4K blocks]
Uncached Write 80.44 45.51 MB/sec [256K blocks]
Uncached Read 38.26 11.20 MB/sec [4K blocks]
Uncached Read 145.76 73.26 MB/sec [256K blocks]
Random 36.21
Uncached Write 13.42 1.42 MB/sec [4K blocks]
Uncached Write 80.88 25.89 MB/sec [256K blocks]
Uncached Read 66.03 0.47 MB/sec [4K blocks]
Uncached Read 118.45 21.98 MB/sec [256K blocks]

With WDE:
Disk Test 19.88
Sequential 21.42
Uncached Write 49.85 30.61 MB/sec [4K blocks]
Uncached Write 21.68 12.27 MB/sec [256K blocks]
Uncached Read 11.30 3.31 MB/sec [4K blocks]
Uncached Read 31.17 15.66 MB/sec [256K blocks]
Random 18.54
Uncached Write 8.65 0.92 MB/sec [4K blocks]
Uncached Write 25.86 8.28 MB/sec [256K blocks]
Uncached Read 24.69 0.17 MB/sec [4K blocks]
Uncached Read 47.86 8.88 MB/sec [256K blocks]

The test system is a 13" MacBook Pro with 4G memory and a stock 250G drive.
Snow Leopard 10.6.3 and Parallels build 5.0.9344.