If I set up a second Outlook profile how will AS handle this?

If I set up a second Outlook 2003 profile using the same pst file how
will ActiveSynce handle the two profiles. I ask this because I did set
another profile but immediately removed it as I was concerned that as
the second user would not have the same contacts and calendar as mine I
might lose data.

I was also surprised to see AS in the taskbar even when the second user
was a different XP account log on. Surely ActiveSync should not install
itself automatically in a new XP user?

Beemer