Saving variable with "big data" produces 0KB Files

Hey everyone, I'm trying to save a variable containing roughly 1 million lines on 8 Cols.

When I try to save it, and I get a dialog box asking me if I want to change the *.Mat format to the newest one, that allows files bigger than 1 GB to be compressed. I approve. Here's the catch - Matlab DOES produce a *.mat file, however, its size is 0KB (no error feedback). In addition, Windows starts making an "error" sound randomly. As far as matlab's concern, the operation seems to be complete and does not display "busy" on the lower left.

Why does this happen, and can this be avoided?

I have good computer specs, so I imagine its not that. I've contacted my local Matlab support representative, who gave me a working, albeit trivial solution of saving in chunks. I hope there's a better way?