Comment # 8 on bug 1205737 from T Adams

Problem solved (in a way), thanks to a bug report on virtualbox.org:

https://www.virtualbox.org/ticket/21312

I reduced memory on the Win7 VM to 2048 MB and fired up one scanner, then the
other.  Both worked properly in the Win7 VM!  I need only remember to reduce
memory to 2048 MB when I want to scan something.

This feels like a stopgap solution, so I won't close this bug report.  Please
feel free to close it as solved, if you think it should be closed.

Please also let me know if you think I should post a thread with this
information on the virtualbox forum.