You’ve come across the Live Rectangle bug which is limited to the MAC versions starting with 10.7 and 10.8, but not 10.9 (Mavericks), see this thread (official Adobe Illustrator Forum): probleme with the handles on new version of AI CC 2014
Since we’ve already experienced some serious problems with the Live Rectangle (snap to grid bug) I’ve decided to write my own plugin (available for free for personal and commercial use) which imitates behavior of the ‘old’ Rectangle Tool. It doesn’t replace the Live Rectangle – it works completely independent!
My Plain Rectangle Tool correctly snaps to grids/objects/points and correctly aligns to grid/points on resize. Of course it supports the SHIFT and ALT/OPTION keys, Snap to Grid and Smart Guides options. In other words it works almost 100% the same as the Rectangle Tool we know from CC (17.1), CS6 and earlier.
The installation package (zxp) adds ‘Plain Rectangle Tool’ icon into the Ai panel (of curse you can assign your custom keyboard shortcut to it as well)

Note: The Plain Rectangle can be easily converted into the Live one using Object > Shape > Convert to Rectangle.
Grab your copy at Free Plain Rectangle Tool and share it with your friends. It’s completely free!!!
I’ve also created a separate discussion (official Adobe Illustrator Forum) https://forums.adobe.com/thread/1587587 for the Plain Rectangle Tool. If you have any comments or request please post it there. Any feedback would be greatly appreciated!