Jack,
I am not able to reproduce your problem. I am running IMAQ 1394 2.0, NI-IMAQ 3.1.1, and Vision 7.1.1. If you have Vision, try running the example program ReadImage.vb from the "C:\Program Files\National Instruments\Vision\Examples\MSVB.NET\1. Getting Started" folder.
Expand the CWIMAQ Viewer so that it displays larger than 800x600 and open the attached picture.
Do you still have problems performing this test?
I would make sure that you have the latest version of NI-IMAQ.
I hope that this helps narrow the problem down. If not, let me know more details such as which version of NI-IMAQ you have and if you have the Vision Development Module.