How can a background thread hang the UI thread?

Question

I am using a background thread to initialize an instrument over USB. The UI hangs when I try to open the device. I would expect the background thread to pause when calling O

Answer 1

How long time does the instantiation of the FancyVoltmeter take? Could it be that it is not the Open method that causes the UI freeze, but creating the COM object (which is done on the UI thread)?

If that turns out to be the case, moving the creation of this object to happen on the new, separate worker thread should take care of the problem.

Edit: I saw now that you already found this out in your comment to Michael...