Old METAR and how to stop updating?

Hi,

I just has a few easy questions:

• Sometimes the METAR are very old in comparision with IVAO Metar. Is this a mistake or is IVAO "generating METAR itself"?
  

• How can I stop the Update during approach? I like to have weather on the ground or after landing, but I hate when the weather is chaning and the clouds switch like I my pants :D
  

I use ASE with FS9 and Windows 7 x64 . I use Autoupdate every 5min.

Thanks mates!