I see yor Post after three years... I've found a similar bug, having faced troubles in inserting/updating long fields. I also used the bind variables available in the Tora sql editor, but I have got no positive result.
I'm using Linux Suse 10 and Tora 1.2.4 (compatible with Oracle 9 - I wasn't able to install newer versions...).
Have you found some solution to your problem?