Hi m3nth:
You do have some control over how often the check for updates run.
From the Start menu, select Programs > National Instruments > Circuit Design Suite > Check For Updates. Then click Settings, and select "Don't run automatically, I will check for updated manually."
You also noted that something keeps crashing. If this something is Multisim or Ultiboard and you can reproduce the problem (a particular file, set of actions, etc), please either contact support (ewbsupport@ni.com, you can put my name in the subject line if you wish support for forward the email to me) or post the file/instructions here so that I can try and reproduce it and ensure that the issue is resolved in the next release.