Writing equations inline in Mac Word
The 2007 version of Word for Mac was quite different from the Windows counterpart and Microsoft didn't maintain a 1:1 release schedule for the Windows version and the Mac version. Consequently the Windows version got ahead of the Mac version and this can lead to some confusion and frustration with the different behaviours when you move between then platforms.

The good news is if you upgrade to Office for Mac 2011 you'll get inline equation editing in Word that works very much the same as the Windows counterpart. And it's as fast as the Windows counterpart on similar hardware.