Are you sure your scanner is trunking the Shawnee system? Sometimes neighboring systems use some of the same channels. Some other you might check are Norman and the State Smartzone.
Check to see what freq the scanner stops on when there isn't activity. Make sure that is one of the freqs with a * or in red in the database (that denotes data channels for that system). Other than that, there could be many IDs that haven't been submitted to the database. If that's the case, figure out who it is (this is the fun part of scanning, I think), a channel description, and submit it to the database so everyone else can use it and know who it is also.