installing for multiple users?

I know this may sound like a contradiction in terms, but I would like to be able to run OOo Portable on a multiuser winxp pro sp2 PC. I use portable apps a lot to simplify software upgrades on a pool of like PCs, as well as on several USB sticks. The former setup involves multiuser support.
Is this possible and how?
My experiments so far yield several problems, some of which may be unrelated to multiuser support, actually.

(in the following description, I use the term "log in" to indicate logging on via the fast user switching winxp facility)

1. User A logs in and doesn't run OOoP, then user B also logs in and runs OOoP. OOo Writer seems to hang, I have to kill it with task manager. OOo Draw works OK, but it seems to hang when clicking on the T tool (text). Pasting text directly from the clipboard works OK.

2. User B exits OOoP and restarts it. Sometimes it works, sometimes it doesn't (nothing happens). I can see with task manager that multiple copies of soffice.exe are running. Killing them all restores the ability to start OOoP.

3. User C logs in while user B's OOoP is running. OOo displays a warning window saying that "some user is already running OOo" and to make sure "to close the other instance before running this one".
This message suggests that multiuser support isn't currently possible in OOo Portable.