Originally Posted by Akira
The card will snap out of the CPU with the slightest bang or vibration to the computer. I know this changes from A600 to A600 but it is a little bit annoying.
The card is also prone to overheating on really hot conditions (ie: usually not in Europe :P). A room temperature of ~30 degrees will bring problems after a while.
I had the same problems in the beginning as the ACA would not stay firmly on the CPU, however I found that cleaning off the CPU pins thoroughly has improved this issue quite a lot. I used IPA and a toothbrush and then finished off with IPA on a cotton bud. After a couple of these treatments, it feels much more 'right' when it is attached and you're not in doubt that it is installed. There is no way mine is going to fall off in transport unless you drop the Amiga on the ground.
Overheating is not an issue I would think. None of the chips get hot enough so that it should cause problems, so I think that is also connection problems. When things heat up, things expand and if you have a few insecure connections, this expansion could be enough to drop that connection.