DWF's created via Revit take a longtime to Open and are slow to Move around in

[boyd.112779]

I have published DWF's from Revit. For some reason they (DWFs) take forever to open and very difficult to move around with. The file itself is really small (180kb).

The model works fine in Revit, no problem. There are several "filled regions and hatch patterns in the model - I am wondering if that could be it. What would cause this? I have not had any other problems with this before.
Thanks,
Boydj.

[scott.sheppard]

If you provide a sample, I can take a look at it.