If dialogue is really sorted correctly, it's probably filtered incorrectly: the error you describe is typical for improper sorting/filtering. To help you out, I'll need more information. In detail, I'll need to know:
- all appurtenant dialogue entries
- the order in which they're sorted
- their precise and complete filter conditions
- their Result Box scripts
- anything I've forgotten to mention
The easiest way to get that information is to have a look at your .esp file. Would you be willing to temporarily upload it somewhere like MediaFire, RapidShare, or the like?