If you are right under the DD you are in their blind spot.
IUb uses Jungmans über DD fix in AI_sensors.dat. I would rather set back these values back to stock values instead of changing all entrys in Campain.RND.mis.
Here are som lines from that readme:
The minimum Sonar Range was changed from default zero to 200 meters.
The maximum Sonar Bearing angle was reduced from -+ 90 degrees bow, to 60 degrees...and further:
The minimum sonar range of 200 m seems to help hide the
sub at depth better so you can sneak away slowly without being detected by the UberSeer
sonar.
In this file there is also Jungman's snorkel fix. I strongly recommend that you use it, so
you need a stock 1.4 Ai_sensors.dat with only the snorkel fix.
I'll upload this file for you and you can replace the one from IUb.
Here is a DL link for Stock 1.4 über DD with Jungmans snorkel fix:
http://rapidshare.de/files/7646704/AI_Sensors.rar.html
You have to replace this file with the one in the mod. It's in data\Library\"Ai_sensors.dat"
Just remember to take a back up from the original one.
Hope it works, Good luck