Have you tried searching for ERROR in Boost and your CRT headers?
In 1.53 at least this is not defined by any Boost headers.

I couldn't find it either.

As I said changing the enum name fixed the problem.

I never had this problem until I included that particular header file. That's why I find it strange.

I wonder if some part of the include hierarchy can by changed to avoid this. This may cause problems for others who cannot easily change a name.

Adi