Exported file turns up empty

I´m trying to export a small mix non-realtime, but it always (except one time!) turns up a blank wav file. With Realtime export this doesn´t happen.

It´s very weird, ´cause it worked one time in my second try! First export was empty, second try worked perfectly, after that second try it hasn´t worked anymore and I haven´t changed anything.

What could be causing this strange behaviour? Don´t remember ever having something like this. Just updated to 5.5.3.

Cubase 5.5.3
Mac Pro 12-core
OS X 10.6.7

make sure none of the tracks is selected, record enabled or input monitor enabled before export.

Nope. I have checked.

I also noticed that the ID3 tag will be included in the file whether I tick or untick the box. :confused:

Did Steinberg mess something up with the 5.5.3 update?