Neither one of my backup programs will copy more than a handful of files before it freezes up, yet Windows Explorer copied 90 GB of files at an average rate of around 50 MB/sec without any problems at all.
Sorry for bringing up such an old post, but I did solve the problem (during backups to an external SATA drive the program would run slower and slower and finally just stall). Once I reformatted the destination drive
and disallowed file compression the problem went away.
Just in case anybody wanted to know.
tanstaafl.