Debugging BASH

I have been trying to use ddd to debug some bash scripts and every
time I run it, following are the results:

Using Ubuntu 8.04 LTS
DDD 3.3.11 (installed with apt-get)

bash --debugger backup.bsh   (works)
bashdb backup.bsh                 (works)

ddd backup.bsh  (bash could not be started)
ddd --bash backup.bsh (bash could not be started)
ddd --bash -debugger backup.bsh (bash could not be started)
ddd --interpreter='bashdb' backup.bsh (bash could not be started)
ddd --interpreter='bash -debugger' backup.bsh (bash could not be started)

ddd --bash -debugger  seems to work, there is an hourglass, and
blinking green square in the lower right. I can do file open source
and load my program, but nothing works. When I try to close - it says
bash is still busy - do I want to kill it.

It seems to work fine for Perl, and all the documentation I have been
able to locate suggest that this is the way to call ddd for bash. I
also searched the archive mailing list and found nothing suggesting
others were experiencing this, or a solution.

I was going to look into see if I needed to get the latest
3.3.12-test6 but have never complied on my computer and did not think
was the application to be experimenting with that task.

Any assistance with this matter is greatly appreciated.