User folder changed after membership changed

Hi group,

I made a mistake: My PC (XP Prof/SP2 is member of a workgroup (not domain).
User "Armin" (that's me ;-) ) belongs to group "Administrators". I
temporarily removed myself from that group and add me to group "users". I
logged off, logged on again - and all my settings were gone! I found the
cause: In addition to
"C:\Documents and settings\Armin" an additional folder
"C:\Documents and settings\Armin.AZSOFT" (AZSOFT is the computer name)
has been created. The latter is obviously used now as the user's folder.

But why? I only changed the membership! I did not crate a new user.

Even after putting me back to group "administrators", the "*.AZSOFT" folder
ist used.

Q: How can I undo this (apart from system restore)? I was an Admin, I am an
Admin - but XP uses a different folder now. It must not do this! This is
a BIG problem, because all application settings, newsgroup accounts and
everything else has to be done again now. It's like creating a new user -
but I have not created a new user! How can I make the user "connect" to
the usual folder that I've been using for month? Is there an official way
or do I have to copy files and do registry hacking?

Many thanks in advance! (really important because I almost can't do anything
at the moment)

Armin