Call support. If you have a test box (as we do not test in production, right...), ipmitool could help. Creating another user looks like it is on the realm of possibility.
'ipmitool set name 3 newguy'
'ipmitool set password 3 somethinglongerthan8chars'
'ipmitool user priv 3 ADMINISTRATOR 1'
'ipmitool user enable 3'
ipmitool user
User Commands:
summary [<channel number>]
list [<channel number>]
set name <user id> <username>
set password <user id> [<password>]
disable <user id>
enable <user id>
priv <user id> <privilege level> [<channel number>]
test <user id> <16|20> [<password]>
That should give you newguy and not have an existing session. But beware, I do not have anything to test against, so this may not work and could be wrong.