Did you change the DIP switch setting just at the beginning that resulted in the 00001100B value being seen?

If yes then consider this: when you have wrapped through the subroutine and come back to the loop (which all happens in a relatively short period of time) you are most likely reading the level of the DIP switch that is bouncing. All switches show this behavior and need to be filtered some how to ensure that the switches are in fact at the levels you expect them to be.

If you search this forum on the subject of switch debounce you can find a lot of discussion on this subject !!

There are both hardware ways and software ways to filter inputs. A software way was discussed in my Puzzler #2 thread from last week. See it here: Puzzler #2.

Michael Karas