Is it safe to update Linux packages?

[zonehome]

I have Zoneminder running on Debian Wheezy. I have not updated the Debian packages in some time because I have been afraid it might break ZoneMinder. Obviously not updating packages creates some risk in itself, so I was hoping for some feedback on whether it's generally a good idea to keep the packages up to date, or whether that has a high risk of making Zoneminder unstable.
Thanks!

[PacoLM]

I have the same distribution running ZM and I keep it updated. I recommend you to upgrade your system, but first do a backup of the database using phpmyadmin.

[zonehome]

Thanks Paco.