I once placed an order with CalcPro, www.calcpro.com, and only received part of it. Attempts to resolve the problem were never responded to, and thus I've never done business with it again.
Now it seems CalcPro has sold pirated books without reimbursing the author, among other complaints:
http://groups.google.com/group/comp.sys.hp48/browse_frm/thread/a4db63204e4e81b7/9c564f6fcc921647?tvc=1#9c564f6fcc921647
It appears this CalcPro may be in the same ethics league as Coburlin, buyer beware!