Wow, I didn't realize this thread was so busy...apparently my email alerts are off.
There was one branching hammer I had that did great for months and then I moved and he didn't quite survive the move.
Since then I believe they have all been wall hammers, so that may be the issue. I will try a branching hammer in a few weeks to see if that is the issue. Never really thought of the m being different to care for. I guess I failed in the research department of this one.