Migrating Discoverer Workbooks between DEV and Production

Imagine you are developing a new Workbook in Discoverer, after you are sure it works fine, you ask your DBA to move the BA and the Workbook to Production, so BA goes through well but workbook does not, because it tell you there is an error like this:
“Cannot join tables used in the workbook. Item dependency “” not found in the EUL”

what next?, besides the possible finger pointing, most of the cases this is a timestamp issue.

if you have Discoverer 9.0.4 you can review the
Chapter 3 "About copying EULs and EUL objects by exporting and importing"
Oracle® Discoverer Administrator
Administration Guide
10g (9.0.4)
Part No. B10270-01

for others version is pretty similar but you have to check the proper guide.