SW2010 SP0.0 Windows Vista x64

I've been working on using the Callout object from C++ with unexpected results.  When this happens, I typically look for VBA examples to determine if the problem is with my C++ or is in fact a systemic problem with the API.  The API docs for the Callout object include the following examples, neither of which is giving me the expected results.

Create Multi-row Callouts  (VBA)
Create a  Callout Independent of a Selection (VBA)

The first example is supposed to create a 4 row callout attached to each pre-selected piece of geometry.  When I run this macro using a simple block with 4 vertices selected, the result looks like this:

The leaders are there, but the callouts are not visible.

When I run the second example macro, I see no callout geometry whatsoever.  No leader, no text, nothing. My C++ code (on Windows 7 x64) was very similar to this example, however the results look more like the result from the first example (leaders visible, text not).

Has anyone else had any luck with Callouts?  Perhaps this is Vista/Win7 specific?  Or x64 specific?  I get the same results using SW2009 SP4.1

Jim S.