The domain import on it's own shouldn't trigger a push install, it's just one way of populating the list of PCs that the Scheduled Push to computers uses.
Maybe check the install times against the Scheduled Push schedule to see if it's working even though it says it's off.
Look in the server log too for the times when the push is occuring. Look on the the clientsfor AeX... logs in the Windows and system32 directories, that may give you a clue too,