Vista - Hearts Card Game: Incorrect Name give to Player

A small but annoying issue with Hearts.
When I play Hearts, the name I am given is not always correct! Sometimes it
gives my name, "Vince", other times it uses "Admin" as my name.
I am the only user of my PC, so I only have one user account, which is a
re-named "Admin" account to my name "Vince" - it wouldn't be too much of a
problem if it was consistent, but it randomly alternates between the 2 names.
This has an impact on the game itself. It is as if it is treating the 2
player names as different payers. If Hearts opens up in with, say, Admin,
and I play a few hands, the next time I open it and it uses Vince, it goes
back to where it was the last time it used Vince, so forgetting all the last
Admin session - if you catch my drift.
Has anyone else had this problem?