ORA-12705 - invalid / unknown NLS parameter (TOAD)

[Quoted] I'm having trouble getting Toad to connect to the database. I've just installed everything on a new computer, and after fiddling some with NLS_LANG registry settings, I got SQL*Plus happy. However, Toad is not, no matter which Oracle home I use. Both have been set to AMERICAN_AMERICA.WE8ISO8859P9. I also sat this as an enviroment variable.

How can I find out whats going on or fix this?

Versions:
WinXP
Oracle 8 db
Oracle Client 9i r2 (9.2.0.1.0)
Toad 7.3.0.0

I've also installed Forms/Reports 6i which also installed SQL*plus 8 and Jdeveloper in case that means anything. I've gotten both the SQL*Plus versions talking to the DB.

thanks,

-- 
Ketil Holden