Unfortunately, I am having the same problem.

ProShow Gold has been flawless for me in the past, but I'm now having
erratic behavior during the DVD burning process that I didn't have before.

I suspect there's something funny with one of their recent updates.
They seem to release updates almost daily(!!).
I've downloaded their latest DVD/CD-R burning updates to no avail.

Now I'm going to try and locate the original installation file I had for
ProShow Gold, and see if it is it's old stable self.  If it is...I'll not
that here, and perhaps make that file available to you if possible.

-Mark

Do you have 2.5_1621?

Did you create shows using version 2.0?
If so, then you may need to delete some unnecessary files.
Here's what the Photodex tech had me do:

Go to the folder where your shows are saved (where you go to click on the
show files you have created to open a show).  In that same folder, you'll
see file folders that have names that start with teh name of the show file,
and end with: "_psdata".

Delete these files.
(This is NOT delete anyting necessary for your shows).

If you recently upgraded (downloaded and installed an upgrade), uninstall
ProShow Gold using Windows Control Panel.
Next, re-install the latest Pro Show version.
(It will NOT make you re-enter the registration key again).
This may solve your problem...it solved mine.

Next consideration:
Do you have Nero (DVD/CD burning software package)?
If so, some of it's included applications can cause problems by interfering
with other applications as they try to access a blank disc.

You may want to uninstall all but what you really use from Nero (I never use
it's media player, and other media handling features, for example).

So far (as of today, and multiple tests later), this has solved my problem.

Let us know how it goes...

-Mark