Applescript with Toast 6 Titanium

A while back I wrote a script that parses a file, opens Toast, adds the appropiate .mp3 files, and then saves a disc image. It has worked great for some time, but recently it has started getting an error sometimes. When the script attempts to save the disc image an error in Toast comes up saying “Couldn’t complete the last command because the disk is full. Result code = -34” This message is in it’s own dialog window. I am saving the disc image to a server, and I know there is plenty of memory for it. This error seems to mysteriously go away when I try running it different times. The problem is that the script just hangs at this if the error message comes up. I’d like to make it so it quits Toast and tries making a disc image from the next file. I can’t seem to find a way to close the window the error message is in. I tried UI scripting with System Events, but nothing happens. Can anyone shed any light on this? Any help would be greatly appreciated. Thanks. My code:

set theMP3Disc to make new MP3 disc
set title of theMP3Disc to MP3Title
add to it items myMP3Files --list of files

--where the final MP3 disc image will be saved
set destOfMP3 to "dest:of:saved:disc:image"
set nameOfMP3File to "MyMP3Disc.iso"
set finalMP3Disc to destOfMP3 & nameOfMP3File
save theMP3Disc as disc image finalMP3Disc
--this is where the error comes up