Hi Susan,
I was able to reproduce the problem you experienced, merging vendors. When you combined Vendor A into Vendor B, you might have lost some of Vendor A's G/L disbursements for merged transactions. Keep in mind that these G/L disbursements are only for drilldown or reference. They aren't the actual G/L transactions. All posted transactions should have been merged.
This problem applies to merging vendors, not changing them. Combining Vendors with different control accounts, did not make the task any harder. It's still supported. That said, control accounts typically have different G/L accounts, so that change should be considered.
AP and DataCare are capable of detecting orphaned G/L disbursements, so a DIC/rebuild, might have removed them.
I'll have a new build of the Toolkit, later today. I'll send you (and Toolkit dealers) a link download the fix.
Sorry about the hassle.