A Flaw in the Spell-Check

I am, in general, an admirer of Apple’s products. They tend to be simple to use, stylish and remarkably rugged. If I have one criticism, it is that they are also expensive — but that is by the bye. I have, however, discovered a terrible flaw in the inbuilt spell-check associated with their Keynote software. It does not like the possessive ‘its’, preferring to treat the word as a colloquial form of ‘it is’. Now, when I write ‘its’, I generally mean ‘its’; and I don’t like a rogue apostrophe being introduced. Heaven knows, I have enough trouble convincing people I am even semi-literate, so I could do without Apple’s ‘help’ in rendering me incomprehensible as well.