Saving binary file consistently fails - anyone know the reason?

Can anyone answer why this operation may consistently produce the following;

save('theResult', 'simResult');

Error using save
Error closing file R:\sp\Testing\ANALYSIS\PRICING\theResult.mat.
The file may be corrupt.

What are the conditions under which one may expect the 'save' function to fail? I will admit 'theResult' is a fairly complex object. but I had no problem at smaller scales. The save docs don't indicate any obvious limitation, and the error message is fairly opaque. Given that the size of the file it produces is about 1Kb, and the failure is immediate, I don't think there was a problem closing the file, but rather a problem doing anything.

Any feedback would be helpful. It would be helpful to understand why...

Answer 1

[Simon Parten]

It could be that setting flag -v7.3 holds the answer to this problem...