Mount Point : / Capacity : 74.4 GB (79,892,106,240 Bytes) Format : Mac OS Extended (Journaled) Available : 56.4 GB (60,511,158,272 Bytes) Permissions Enabled : Yes Used : 18.0 GB (19,380,944,896 Bytes) Number of Folders : 59,204 Number of Files : 240,853 As you can see I have 56.4 GB available. Again, nope. I usually have firefox open and the Mac mail utility just sitting there. But I will try again after closing all application other than HiMD. I realize that I have connected thru a midi port expander -- aha!! very suspect as I think about it. I'll try without that. Since it doesn't happen every time, I may have to try for a day or so to see for sure if the problem is fixed. Thanks for the response. It is very helpful to know that it is probably limited to my system/setup/hardware. I originally suspected that there was a known bug and was looking for a patch/update, but I see that many, many people are successful with the software, so it must be my system. I'll post when I have more data. Thanks again.