QNTC failure - CPDB053 - caused by special character?

I was getting CPDB053 - Error Exchanging Security Information,

Specifically, Error Class 1 Return Code 5 which per the message text means
- Access denied.

In the netlogon.log of the WIn2003 DC, I see:
11/27 13:51:28 [LOGON] domain: SamLogon: Transitive Network logon of
domain\MYUSER from SYSTEMI (via THEPC) Entered
11/27 13:51:28 [LOGON] domain: NlPickDomainWithAccount: domain\MYUSER:
Algorithm entered. UPN:0 Sam:1 Exp:0 Cross: 0 Root:1 DC:0
11/27 13:51:28 [LOGON] domain: SamLogon: Transitive Network logon of
domain\MYUSER from SYSTEMI (via THEPC) Returns 0xC0000064
11/27 13:51:28 [LOGON] domain: SamLogon: Transitive Network logon of
domain\MYUSER from \\SYSTEMI (via THEPC) Entered
11/27 13:51:28 [LOGON] domain: SamLogon: Transitive Network logon of
domain\MYUSER from \\SYSTEMI (via THEPC) Returns 0xC000006A

Which per this page:
http://support.microsoft.com/kb/189541
0xC000006A User logon with Misspelled or bad Password
0xC0000064 User logon with Misspelled or Bad User Account

I also found this IBM doc
http://www-01.ibm.com/support/docview.wss?uid=nas8N1018627

Now, I double and triple checked that my use ID and password matched
between Windows & the i. I could in fact access the IBM i Netserver from a
PC without issue.

running 7.1 with password level 0 (yeah, that' son my to change list)
PC in question is running WinXP.

My password was 6 characters, 2 digits and one special character, a dollar
sign $.

I changed both Win & System i passwords, and removed the $ and QNTC worked.

I've been unable to find anywhere that lists special characters to stay
away from if you use QNTC...But I expected the simple ones, @#_ to be fine..

Apparently not. Does anybody know if and where this restriction is
documented?

Thanks!
Charles