I can give a bit more details:
Microsoft Word .DOC format is not publicly documented. It is a proprietary format. There are only a few applications out there other than Microsoft Word that can read and write DOC files. The key is that all of them do this with a varying degree of nastiness. All due to the fact the format is not documented.
Some vendors support more features of the DOC files than others. We've spent countless hours on DOC import and export in Aspose.Words and believe our support for DOC is one of the best. If you try open/save on any complex DOC file in other applications or libraries you will see a lot of document content and formatting will be lost, such as fields, revisions, ole objects and so on.
From what I know AdLib can work via Microsoft Word Automation or directly through their native reader/writer. Probably you are using AdLib in the native mode. It will be hard to say whether the problem is caused by AdLib or by Aspose.Words. It might be that Aspose.Words writes a perfectly valid Microsoft Word file (all MS Word versions open it as well as other applications Open Office etc), but there might be a few bits set in a way that AdLib does not like it.
Unfortunately, it will be quite difficult to track down and fix because as you can imagine AdLib is a sort of competitor to Aspose.Words and they might not be willing to cooperate much. In the past I tried downloading evaluation versions of AdLib, had problems and really never heard back from their technical support. I don't even have AdLib running here in a test environment to see what could be causing the problem.
Due to all of the avove the problem with the DOC file in AdLib might be difficult to fix.
As Alexey pointed out correctly, you have an option of switching to the Aspose solution completely. Use Aspose.Words + Aspose.Pdf to produce PDF files.
Also, you can try using Aspose.Words saving RTF, WordML or DOCX and then passing this to AdLib. If AdLib fails in this case, but MS Word opens these files, you will be able to confront AdLib and ask them why they can't open a valid file. You will be able to claim these files are valid because these formats are documented and can be verified against the specification.