[Scip] Annoying error keeps reoccuring: "objective limit was reached during optimization"

[Thomas K. Stidsen]

Hi Everyone

We are currently developing a Branch&Price algorithm in SCIP, but we 
keep encountering
an annoying problem: On some of the test data samples SCIP returns: 
"objective limit was
reached during optimization".

This is a mystery to us. We have tried several things to avoid this problem:
- introduced upper and lower bounds on ALL variables
- introduced a special constraint which simply sets an upper and lower limit
   on the objective function limit.

Still we encounter this error message. It only occurs after we introduce 
a number of branching
constraints.

We are using cplex 9.1as an LP solver.

When the problem occurs, the LP problem is rather large and hence 
difficult to "debug".

We will very much appreciate any help.

Best Regards Thomas

-- 
Thomas Stidsen                       Associate Professor
Email:                               Email: thomas at stidsen.dk
Phone:                               Tlf. : (+45) 45 25 33 84
IMM, Technical University of Denmark