I'm running air applications on Mac Mini computers (predominantly running 10.7.2) and am finding that after a few weeks of running constantly the air app gradually slows down, then grinds to a halt. The applications are dynamic animations that run full screen 1080p - they are artworks that are left on constantly.
It then becomes impossible (or very slow) to quit the air app and the whole computer will respond very slowly or not at all. After this has happened a few times the computer will not even restart and will need the system re-installing.
I've tried running various statistics outputting things, like MR Doobs Hi-Res-Stats - so I can monitor the framerate, memory and children. There are no obvious problems there. The cause of the issue is very hard to debug as it initially takes weeks for this error to occur, though after that it re-occurs more frequently and seems to affect the Mac OS too.
The Mac mini is a 2.5GHz Intel Core i5 with AMDRadeon HD 6630M 256MB graphics. This model does not have automatic graphics switching which i've seen can cause problems.
I am currently upgrading the os and seeing if that will help, but it will probably take weeks of constant running to see a repeat in the issue.