well if a quirky calculator is the worst thing that happens on unsupported mac harware i will take that all day long, its a small price to pay to keep this machine aliveSorry to hear. Looks like Calc behavior is different on different models (not surprising). On my MBP6,2 (non-metal Nvidia Tesla), I open Calc, toggle display mode to Sci and back to Bas and then I can calculate without the NaN problem. Sometimes I have had to do a simple multiplication and Clear in Sci mode before switching back to Basic. Sorry that didn't work for you.
I don't want to be in the software maintenance business. Fortunately, the change is simple enough that most can do it.
Also, if I'm paranoid about software that I download directly from Dortania, can you imagine how paranoid I am about downloading software from other sources? There's another Bernie Madoff or Sam Bankman-Fried lurking out there somewhere.