Every time I have updates, Ubuntu 12.04 demands a partial upgrade - but the partial upgrade insists on removing QGIS and GRASS, two GIS packages that I use. I don't want to loose these packages (which both work fine). How do I force Ubuntu to leave them alone, without jeopardizing my security? I also do NOT want to "upgrade" to anything newer than 12.04. The last upgrade I had to make (10.04LTS to 12.04LTS) required a few days work to eliminate the "Unity" and get things working under an acceptable (working) Gnome desktop - much of the (private) specialized software I use didn't like Unity. (I will NEVER use Unity, which I despise!)
(Edit: this has been going on for maybe 2-3 months now, and is very irritating - and Update Manager now will not update the kernel without first doing a "partial upgrade".)