Unexpected output when converting to an integer with int()

Isn't the real question, what happens with Atmel Studio on a naked 328P with all the latest packages?

Not sure. Haven't tried Atmel Studio. Is that an application only for windows?

The issue may just be with the AVR-GCC math library. Arduino does not package the latest version of AVR-GCC, so we could be looking at an already "fixed" issue.

Thank you for suggesting it may be something with the AVR-GCC math library. Don't think I'll have time to compare the latest version to whatever is implemented in the Arduino software (am simply using the Arduino project Version 1.0.5) .

Looks like I was not the first one surprised by this! Check out this link:
http://8515.avrfreaks.net/index.php?name=PNphpBB2&file=printview&t=80319&start=0

Things like this can get under ones skin [...] bought an HP67... And never looked back!

The HPs are nice calculators!