I've seen this in Excel before without any external references. It happened, as with your problem, on an Exit Function call. Excel doesn't seem to have a /decompile option, but I fixed it by making a change in one of my class modules, executing a compilation from the Debug menu, and then undoing the change. I suspect that one of my class modules had mis-compiled for some reason, and Excel won't re-compile unless it thinks something has changed.
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