You're right, it's not implemented properly. There's many things that work with VB, but not CBuilder. You've just come across one of them.
Our solution to almost all such problems was to use Visual Basic to create a simple ActiveX wrapper for the MapPoint OCX. This wrapped control is what is used in Builder. When things like setting the name don't work directly, we add a simple Get/Set routine to the VB project and do it there.
Basically, Visual Basic acts as an interface to make those handful of calls that fail in Builder directly.
Cheers,
Chris
VP Sales & Marketing
www.mobileiq.biz