It's returning the correct value, yes. However, the problem is you're testing for an incorrect value. "1" and 1 are not the same thing; the former is a string containing the character "1" (in ASCII, hex value 0x34). You're comparing that with the number one, hex value 0x01. Since the number 0x34 does not equal the number 0x01, your if() statement is correctly evaluating to false.
Either test for the correct value, or use the "equal" operator and not the "identical" operator. See [man]operators.comparison[/man] for more information about PHP's comparison operators.
EDIT: Furthermore, I'm confused why your first post talks about MySQL, yet the code you've shown us above has nothing to do with MySQL and everything to do with external POST'ed data from an HTML form.