Yes, I am feeling very good about a quick fix for this. It involves changing simple values for those of you who want to fix it now, and not wait for the full modelling treatment that I am now determined to give it for our next version.
I am going to change the "good" AI sonar to have geometry identical to the FFG towed array (the only other passive array modelled without a deadzone, I am using this model to avoid the potential bugs that could come from doing it another way) with sensitivity similiar to Pelamda and max speed near the TB-23 (I have to play with this to see what seems right, since this also effects ships for the time being).
As for the "bad" sonar, for subs without a TA, the geometry will stay the same, but I will make it essentially equal in sensitivity to the Kilo cylindrical array.
I will post the exact values and a instructions on how to make the changes via Ludgar's editor soon.