hmmmmm....yeah, Tab won't work too well in there. I don't have a great deal of control over how that key acts in the program, unfortunatly, it just does what it wants realy. You could try turning off Mouse Support in the options screen, that MAY help, as it will 'disable' most of the screen, therefore taking away anything for the program to Tab to.
If this doesn't work, I'll have to disallow Tab from being an allowable key to map to.