Multi page report running as Excel - Issues - COGNOS11.0.12

[firefly]

Hello

We are testing our reports in cognos 11.0.12 (our soon to be production environment)

We have few reports that runs fine when we run them as HTML. But takes forever when we run them as Excel. I understand that HTML version just give ths top 20 or 25 columns and I shouldnt compare the performance with HTML and Excel.

But when we do a page down in HTML or when we schedule the report as HTML , it takes only few seconds to run.

These reports are multi page reports where each page has its own query. Also there are few singletons on few pages.
we did a UDA trace which was recommended by IBM and saw a strange behavior. When we have the UDA trace ON the report runs fine in EXCEL without any permanence hiccups.But when the UDA trace is OFF, the report takes forever to come back. Has anyone experienced this ?

Also we did couple of other things. we did fiddler traces, F12, etc., But no luck.

we also have another NON Production instance of Cognos 11.0.12.. where the report runs fine in E Excel in few seconds. We compared the configuration settings , we double checked everything that we can and it both these instance point to the same Database. The only difference between the NON PROD instance and soon to be PROD instance is that the PROD instance is pointing to our current PROD 10.2.2 content store.

We are scheduled to roll out this version to our users in few days and would need this situation sorted out before we go live. Any suggestions would be helpful.

Thanks