I dont know if this helps you in any way, but when my 'move' tool makes gooffy stuff i usually try to check the settings for the tool.
I don't know any other way to check it than this:
Go to -->Modify-->Attribute Paint Tool (Option Box).
The paint options appears on the right screen as they always do.
Then you click on your move tool shortcut, and some different settings for the move tool apperas.
What makes my tool gooffy, is the check box for 'discreet move.' If that button is checked my move tool acts gooffy.
Uncheck it / check it, try some other stuff.
Also remember; if you have 'caps lock' turned on, it REALLY acts weird.
Hope that helps you!
Good luck :-)