Mapped Drives

After applying the latest security updates from last week
some of my XP work stations, Personal mapped drives are
not reconnecting at log on and the check box reconnect at
log on is checked. I do have a logon script that map's
network drives no problem to the same server. It is just
personal drives that are manually mapped that are not
reconnecting at logon. Wondering if any one has run into
this probelm.

Thanks