Pelles C doesn't know \a as a switch to right align shortcuts in menu items.
This doesn't work neither in resource scripts nor with AppendMenu.
See: http://msdn.microsoft.com/en-us/library/windows/desktop/aa381024%28v=vs.85%29.aspx (http://msdn.microsoft.com/en-us/library/windows/desktop/aa381024%28v=vs.85%29.aspx)
I expect Pelle just passes the string, he has no reason to alter it so it's unlikely to be a bug.
John
He changed the string, but wrong. He doubles the backslash!
He should translate \a to \0x08 instead! (\b is working)
Alternatively one can treat this as an error in the MSDN documentation, because the actually working value is not \a but \b. :-)