Sorry for the late respond guys, have been kinda busy recently.
@hellfried, thanks for the info about VirtualBox, if possible, you can help contribute abit regarding the pros and cons and add some snap shots along too. So maybe later on I will request moderator to merge your posting to the topic post.
@hidayat, as many PD users out there, I didn't encounter any problems using PD 4.0 to run WinXP. Just make sure you tweak the right resource allocation for your virtual machine in order to run those programing apps you mentioned without any hiccups. As said before, if you need to run apps with full native resource, use Bootcamp.
@dennisccy, maybe I'm not in a position to advice you upon VMWare Fusion problem, but make sure your copies of VMWare Fusion, Windows XP or Vista, and your Mac OSX are all up to date. As your description is quite vague, I also cant pin point what's exactly the cause. If you do have setup BootCamp, I would suggest try booting your Windows with BC to check whether it is your Windows problem or VMWare instead.