I have a POS with two computers. The main computer adjusted to the correct time this Sunday just fine. But the secondary computer -networked to the main-will set at the proper time when I push the Synchronize button. But every time I open the operating software, the time flips back an hour. It happens every time the software begins to load. Err! Any ideas?

You haven't told us what type of "operating software" you are using. In fact I don't know if "operating software" is even the correct term. Typically a computer will load an OS - Operating System - when it powers on. e.g Windows XP, OS-10, Linux, UNIX, etc. Once the OS is up and running, any number of applications can be loaded and run on the computer. Since you say that you "open the operating software" after hitting the "syncronize button" (whatever that is) it sounds like you are opening an application sometime after the OS is up and running. Assuming that's the case, I would suggest that you speak to whoever is responsible for maintaining your software and ask them why the application doesn't recognize the fact that DST is in effect.