You spend money to beef up your network security all the timre. Isn't that a form of "future problems"?
Nobody says a company will migrate eveything over in one quarter. Place I worked for took over 9 months from the time they purchased the computers to the time the migration was done. In the mean time, dead laptop batteries were replaced, cleaned up some licensing issues [a few illegal pieces of software installed] and standardized on others. Went from a dozen different FTP software clients to one that is supported.