i recently switched to MP after hasseling too much with mce2005 for
the last two years.
i am very happy with it, even if i know that developing such a complex
piece of soft needs a high amount of professional work.

you all
for that.
but that the team
won't support running MP
with limited user accounts
on XP is not the right decision imho.
even though i dunno use vista i am happy to hear that MP runs smoothly
on that system with a limited user account.
i solved this issue for me with giving all MP-related files full control for the
user with limited rights. not perfect but better than work only with administrator
privileges.