Networking issues or hard drive issue?
I am also having slowdowns on Windows XP. I have MacBook Pro 2.33ghz/4gb ram with PDM 5582. I have been using Parallels for a little over a year, and have been at this version since the date it was released.
All of a sudden, my system got very slow; I started looking for causes, and did my normal maintenance including making sure I have free space on my Bootcamp paritition and doing a Norton Systemworks Speed Disk as I have been doing. I checked my CPU Usage using Task Manager, and it showed a steady 100%!!! I tried closing processes, and still 100%. Finally I started disabling Parallels services one by one, and although when I disconnected from the network it gave me a momentary lessening of CPU usage, it jumped back up after a few seconds.
Then I started to look to see if my well-intentioned maintenance may be causing ill effects. I am now doing a Windows XP Disk Defrag, and my CPU Usage during the Defrag is MUCH less - Perhaps it is a process continually reading and writing to the disk which is causing the problem - or perhaps Norton SystemWorks is doing something to the partition.
Just my temporary 2 cents worth... I'll come back with more info when the defrag is done ... and when I know if the CPU usage stays down... (currently from 6 to 30 % - a huge difference!).
My VM has 672 MB of Memory with a Adjusted memory limit set to "Automatically" and "Enable virtual memory preallocation".
Added: My WINDOWS XP Disk Defrag (as against other defragmenter) finished, and low and behold, my CPU Usage is now at a range of around 3-6% with an occasional 15 or so! Perhaps 3rd party defragmentation actually is dangerous to use with Parallels 5582??