VERR_GENERAL_FAILURE importing Oracle SOA Pre-built VM

I downloaded and tried to import the pre-built VM for SOA on VirtualBox (in my 64bits Win 7 laptop), and I found this error: Could not create the clone medium (VERR_GENERAL_FAILURE).

After googling and finding nothing useful, I cheked the MD5 sum of the downloaded files. One was incorrect. I downloaded it again and the VM worked without problems.

I never before bothered cheking the MD5 sums, but I guess I'll do it from now.