If you select the Magnet tool from the toolbar, you should be able to hover the mouse over a magnet, then click-and-drag it to a new location.
If that's not working for you, you may want to send some screenshots to the
support ninjas so they can investigate the problem with you.
(You can take a screenshot by pressing command-shift-4, which will give you a selection cursor. Tap your Space key, click on the window you want to capture, and when you release the mouse the image will be saved to your desktop as 'Picture 1', 'Picture 2', etc.)
You can then drag the images to an email message and send them to the ninjas. We can often use the information they contain to figure out what's going on.