G4ChordFinder error - Exceeded maximum number of trials

Hello,
I am getting the following error:

-------- WWWW ------- G4Exception-START -------- WWWW -------
*** G4Exception : GeomField0003
issued by : G4ChordFinder::FindNextChord()
Exceeded maximum number of trials= 75
Current sagita dist= nan
Max sagita dist= 2.56e-05
Step sizes (actual and proposed):
Last trial = 1.92294e-78
Next trial = 1.92294e-79
Proposed for chord = 3.84587e-78

but only when I launch electrons from a point where the electric field is very high. The program does not issue these errors when electrons are launched from lower field regions.

I set the deltaChord using the following statement:
fChordFinder->SetDeltaChord(0.0000001*mm);

and I also have the following statements:
fFieldManager->SetDeltaIntersection ( 0.00000001mm );
fFieldManager->SetDeltaOneStep ( 0.00000001
mm );

Should I perhaps have different values for these paraemeters in different regions of the electrostatic field according to the strength of the field ?

Best Wishes
Chris