Temp Dir space Error 0x23e0b00f

Disk Master Pro 3.9.2 - New install on Windows 7 x64 sp1.
Creating a new disk backup.
Required space 53.17GB - available space on disk 573.23GB
I am getting this error:

The space of the temporary directory is not enough to complete the task, please check the temporary directory and try again. (ErrorCode:0x23e0b00f)

Where is this temporary directory?
I have set the Windows Temp Dir on a separate partition with 4.79GB free.
Why would the program need more space? If so is there a way to change the path in the program to point to another partition with more space?

Thanks,