Disk Utility memory error

When I attempt to make a DVD/CD Master .cdr, Disk utility displays an error that not enough memory is available on my drive. I have 110GB unused space on the drive. I even tried to create the .cdr on a 1TB external drive but the same error came up.

20" 1st Gen iMac Intel core duo
500GB HD
Snow Leopard 10.6.8

UnclKracker said:

When I attempt to make a DVD/CD Master .cdr, Disk utility displays an error that not enough memory is available on my drive. I have 110GB unused space on the drive. I even tried to create the .cdr on a 1TB external drive but the same error came up.

20" 1st Gen iMac Intel core duo
500GB HD
Snow Leopard 10.6.8

Click to expand...

It would be helpful if you quoted the error EXACTLY as displayed, but I'm going to assume it said this: There is not enough memory or disk space to complete the operation.

Oddly enough, I found some troubleshooting tips for this on Microsoft's website. It was addressing a problem in using Office for Mac, but these tips apply to anything.
"There is not enough memory or disk space to complete the operation" error when you start an Office for Mac program

UnclKracker: RAM is memory. Hard drive space is correctly referred to as "storage."

Maybe that sheds some light on the error?

I'm working on the troubleshooting advise but in the meantime here is some more, hopefully useful information.
The exact error when creating a .cdr file is:
Unable to create "PSE 9." (No space left on device)
I've also discovered a related error when backing up an iPhone
iTunes could not back up the iPhone " myname iPhone" because not enough free space is available on this computer.

UnclKracker said:

I'm working on the troubleshooting advise but in the meantime here is some more, hopefully useful information.
The exact error when creating a .cdr file is:
Unable to create "PSE 9." (No space left on device)

Click to expand...

Here's a thread from Apple's site with a solution for someone with a similar problem. Basically they weren't doing it right.
https://discussions.apple.com/thread/2226809?start=0&tstart=0

I've also discovered a related error when backing up an iPhone
iTunes could not back up the iPhone " myname iPhone" because not enough free space is available on this computer.

Click to expand...

This is more puzzling, especially since you say you have 110 GB of free space left. You may have an underlying problem causing both these issues. The very first thing you need to do is make secure backups in case the drive is failing. Once done, grab a good SMART monitoring utility to get a detailed analysis of your drive. DriveDx is a new one that I highly recommend. You may want to run a Full Self-Test (found under the self-test submenu).

If the drive checks out, then go back to the basics. Download Onyx and run its full suite of maintenance and cleaning tools. Then see if all is well.