I was able to duplicate your apparent Forms Control .enabled anomaly in Excel 2010. Apparently the .enabled property works as expected in Excel 2003 (tested by me) and in Excel 2007 (anecdotal evidence from another thread).
I was successful in disabling a Forms control using the .enabled property as a software switch (see the attached file and the code that follows). Another alternative is the hide (.visible = False) the CommandButton when it is supposed to be disabled.
In an ordinary code module such as Module1:
Lewis
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