I believe the problem is with systems that are transmitting in SNFM mode and especially when the system with the problem is not a very strong signal. (SNFM=super narrow FM. On newer Uniden scanners it's referred to as NFM-narrow FM.) The PRO97 does not have the circuitry to properly decode a DCS code that is transmitted in SNFM, so I doubt you will ever see a fix for this. Some users don't have a problem because you don't notice it as much when it is a strong signal.
I've seen this radio have trouble decoding an LTR talk group ID when the signal is marginal. I think this is the same issue.
What I have done to deal with the problem is I have set all the DCS channels to DCS search. That way if I ever have trouble with interference on that frequency I can hit "Enter" the next time the channel is active and store the DCS code displayed. Out of 500 or so channels I scan, I only have about 4 that use DCS so it really is not too bad for me.
Doesn't take away from the fact that this is a great radio for the price you pay for it. I love it anyway.