Problems with Windows keyboard on Mac

I recently hooked up a Windows keyboard to my Mac. It works fine except for a couple problems.

For example, in FireFox, I can use the Home key to move to the top of the page just like in Windows, but I can't use the Home key to move the cursor to the beginning on a text field.

Also, the left arrow key just plain doesn't work. This might be a problem with the keyboard itself but I don't think so - my friend was using the same keyboard on a Windows machine for a long time before I took it back and never complained of a non-working left arrow key.

Is anyone else having problems like this?

Thanks,
Jason