DTBook to EPUB3 conversion extremely slow


We have a number of DTBook files to convert to ePub3. The simple books convert reasonably fast. The complex books take a *very* long time for the Pipeline to complete, approximately 18 hours to several days per book.

We are using both Mac and Windows computers with similar results.
Current versions of Java, Pipeline 2, and Safari or FireFox.
Windows computer: Win 7 Pro, 64-bit, 8GB RAM, Intel Core i7-2600 CPU @ 3.40 GHz

If a developer contacts me, I can send an example for testing/debugging.

Hi Dennis,

Thanks a million for the feedback. May I have one of those dtbook files please? my email is capitan.cambio at gmail.com