Sounds like the locations aren't the issue then. Although I'm not familiar with those WAPs and how reliable they are at maintaining a connection. As mentioned before the 8X is notorious for having wifi and connectivity issues. It's really a bad design unfortunately.

Couple of things. You're not on the latest firmware of .69. You're about 4 or 5 revisions behind. There is also a wifi hot fix for the 8X but you need to ensure which wifi version you have...Atheros or I believe the other was Intel. Don't apply the hot fix unless you're sure. There's also a setting on the 8X that allows you to toggle something to the effect of 'allow windows to manage the wifi' or something like that. Don't have one in front of me. The 8X has been disco for a while with a newer and slightly more reliable wifi version 8X-GA. That may solve some of your problems. Are these panels wifi only or do you have hard Ethernet to the dock as well? I know some had problems switching between the two and would require a reboot.

I would start with the firmware update and if that's not sufficient contact TS for advice on the hot fix, repair or upgrade to 8X-GA. Obviously newer panels or iPads will be more reliable but at qty 22 plus all the programming it's going to be $$$$.