Database size limitation in SQL Virtual Database?

I'm currently using the sqlVDBcmd.exe version 8.4.1.130, and having trouble virtualizing a large backup file.  The .safe file is compressed (and mapped) at 730GB.  Inside that backup file is a database that is over 2TB.  All of my disks for the backup file and the virtual DB files are a GPT disk (one of them is 3TB).

For whatever reason, the CLI hangs and never mounts the database.  Using RESMON.exe, I can see the disk read/writes for about 15 minutes, then disk is idle.

I'm able to mount smaller virtual databases, but not these large ones on this same host.  I've also tried several full backup files with no luck.

Has anyone had this problem, or run into a large size limitation with SQL Virtual Database?  If not, what is the largest sized .safe file (and total DB size) that you've mounted with it.

Note: the SQL Safe version is 8.4.1.105 (not .130 - to avoid SQL Safe Console bug where restore progress doesn't display).