I am using chemstation F.01.03.2357 with GC/FID for integration of hydrocarbon ranges. Two surrogates elute in this range. Automatic calculated concentration proceeds correctly, subtracting out the area from the two surrogates. When I perform a manual integration on this range, it adds back the area for the two surrogate compounds. Is there a patch for this error? I use other versions of software on other instruments with no issue.