[PD] Best windows version for PD

I've been been running PD under linux, and have developed a few patches which are entirely MIDI based. Upon loading them in windows (XP) I noticed that XP seems to have enormous troubles with timing. If I set up a simple metro object and have it trigger a click via midi the result is all over the place, the timing is horrible "click click click click". I admit I am using the crappy gameport Midi out on my SBLive, however under linux the timing seems quite solid from the same device. I was wondering if Windows 2000 might do a better job, does PD in general run better under 2000? Would my problem be solved if i bought a real midi interface, or is it an OS related issue as I expect...?

Thanks in advance,

Jonathan