Has Anyone Got TOra 1.2.4 On Linux Working Against Oracle Database 10g?

I've been trying to get TOra 1.2.4 to connect to an Oracle Database 10g installation, with both client and server on the same Red Hat 9.0 machine.

Unfortunately, although TOra starts up, as soon as I try and connect I keep coming up with the error "ORA 12705: invalid or unknown NLS parameter value specified", even after setting the following environment variables

ORACLE_HOME=/home/oracle/product/10.1.0/db_1
ORACLE_SID=markr10g
PATH=$PATH:$ORACLE_HOME/bin
NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P1

I've posted a message to Henrik and the same problem's been mentioned on the TOra forum recently. I've made sure the version I'm running is the one from the TOra website (rather than the RedHat supplied one, which doesn't come with Oracle connectivity), but so far, no luck. iSQLPlus and SQLPlus work fine.

Anyone got any ideas?