Drawing is blank when reopening

Hi,

I'm probably mking an obvious mistake..

After saving and reopening a drawing all I get is a blank page.  

Things I've tried:

I've zoomed into the space where the drawing should be
I've set auto zoom in Application Preferences > Defaults > Auto Zoom on Opening
I've udpated to 2.2.0.2
I've tried View > Redraw
I've checked that when I open the file the doc type is set to Document Exchange DXF not QCad

Interestingly, when I open the same file using File > Recent instead of File > Open it works fine, dispalying the drawing properly.

I've attached a typical file for reference.
23.dxf


Any ideas?

Thanks in advance,

Jim