Thanks 123. Upon some investigation, I had two issues: on one touch screen I had it pointed to my ddns address so it would have always asked me for a username and password no matter what (your post helped me to realize this, many thanks!). On the other touch screen with a local address, I was asked only a password eachtime, but the prompt was through the automation browser instead of the username/password iexplorer popup. This was due to an incorrect setting of "promptwhenswitching" found under each user account. It appears by default this is checked, but must be unchecked if you don't want to type any passwords each time (see attached pic).
Out of curiosity, is it normal to lose the SYS connection (through the automation browser) once/day? I have a touch screen that loses it's connection to SYS. Upon the first tap, everything looks normal, then I get the automatic reconnect screen and it reconnects. Any ideas? I checked the wireless power saving setting on the touch screen and it appears to be disabled. To provide internet to the SYS server, I do use a wireless dlink bridge connected to a switch. I have all ip addresses permanently reserved in the routers DHCP table though so I would think the wireless connections should be constant.