memory trampling

Apologies in advance if I don't provide adequate details on this
problem. I have a kind of chimp-like understanding that my approach
is
wrong, but I don't understand exactly why it's off and I'm looking
for
some help. I have a library that I'm linking to that takes pointers
to
a particular kind of obj and adds them a processing thread.
AddObj(A* aPtr)
I'm making a library for people to use that thread without needing to
know a ton about the implementation details of that, they should be
able to just make a simple friendly type, say WrapperA and call
initialize on it.
WrapperA wa;
.....
wa.init(2500, SINE, 100, 1.f);
WrapperA holds an actual A*, which it then instantiates and passes to
the AddObj method, so:
void WrapperA::init(int length, int order, double coefs, float range)
{
        ASubClass* (a) = new ASubClass(length, order, coefs, range);
        Delegate::getInstance()->addObject( (A *)a );
}

My singleton there has the actual thread object, so it just gets the
pointer and adds it to the thread:
void Delegate::addObject(A* obj)
{
        thread.AddObj(obj);
}

That causes a EXEC_BAD_ACCESS when the thread actually does its
processing because the memory is getting trampled and I GDB can't
reconstrcut the frame:
previous frame inner to this frame (corrupt stack?)
Now, I'm not super savvy on what exacty the thread does with that
memory, but I've played around with it a lot outside of my little
wrapper library scheme and it works fine, so the problem is in my
implementation. I'm thinking my whole "make this thing friendly for
the non-pointer savvy" is a little silly, and I'm probably going to
scrap it, but I'd like to understand why the memory is getting
tramped
here (if that is what is in fact happening). Thanks and I'd be happy
to provide more details if there's something important I haven't
provided.

josh