The only time I have trouble is with certain types of vacuums, A/V equipment, LCD and plasma screens, and flouresant lighting.... Still wont take them out, I get the manufacturer to recongize it as a known problem, or "equipment conflict", explain this, and the code to the customer and leave... What they do after I am gone is thier bussiness.
Personally, I think the AFCI is the product of sucessfull 'Lobbying' by thier manufacturers! They are still in thier infantacy as a technology, and may not be as reliable as promised down the road. Much the way GFI's were, until not long ago. A nussiance if they worked, and false security if they didn't.