OT: Exporting a BASH prompt from a script

[Hal Vaughan <hal@thresholddigital.com>]

I'm having a strange problem.  I've installed some new systems and I can
change the prompt as I want, but if I write any kind of script, and change
the prompt within the script, it doesn't change the prompt.  This is even
with a short 1 line script that does nothing but change the prompt.

Here's the prompt I'm trying to use (which includes escape characters, which 
seem to be causing the problem -- bash seems to see them as commands):

PS1="\e[35;40m[\u@\h:\W]\\$\e[0m "

I know my old .bashrc changed the prompt (only PS1), but I don't remember
doing anything other than PS1="{my prompt}" to get it to do that.  Now it
won't work.  I tried to export PS1 so it would be available outside the
script, but export didn't like some of the characters in it.

So how can I export a prompt I create in a script (like .bashrc) to use
outside the script (in normal command line)?

Also -- any idea what could allow this to work in one system and on in
another?

Thanks!

Hal