Performance decrease with Visual COBOL 2.0 v. Native COBOL

We are converting a large admin system to managed Visual COBOL 2.0 from native Net Express 5.0 and have noticed a significant performance decrease in our batch processes. Running the same process on the same PC with the same data, Visual COBOL appears to be up to 4.5 times slower than the natively compiled code. I read in one post that a configuration setting to license manager solved the problem and in a prior incident report switching from comp-3 to comp-2 was a work-around. Are there any performance tuning tips you can send my way?