Is there a way to completely disable overseas shipping? I've unchecked all the overseas possibilities with ausPost, but that darn Fixed Cost keeps getting invoked.

I've tried setting the Fixed Cost #1 field to 0 (as indicated in the commentary to totally turn it off) and to 15.00,0 (in an attempt to enable $15.00 flat rate for local shipping, disabling overseas), but nothing sticks. An overseas customer is presented with a $0.00 shipping cost (not a good thing).

Running ozPost 3.6.5 (yes, I'll be updating to 4.0.1 shortly) on Zen Cart 1.5.4.