I downloaded and installed the trial version of TI 10, build 4871. On my first pass of backing up "Data Files" from my C: drive I did a direct burn to my DVD writer; that was painfully slow, so I cancelled it. On my second pass I created the folder on D:\acronis and defined it as a backup location. I also went into Tools --> Options and set my split size to the canned value of 4.3GB, then restarted a backup of C: drive. While it was running I read in these forums about some possible file size/ISO format issues with large files, so I canceled my backup again and cleaned the .TIB files out of D:\acronis On my 3rd pass I went into Tools --> Options and set my split size to the user-defined value of 1492MB and restarted my backup of C: drive. When I finished, the files in D:\acronis were sized as if my split size were still set to 4.3GB-ish size. Here is screen shots of before and after: http://easy48.com/acronis/split0.gif http://easy48.com/acronis/split1.gif http://easy48.com/acronis/split2.gif Any suggestions? I even rebooted my computer and restarted TI10 with the same results: I set the split size to 1492MB, it insists on making larger .TIB files.