Hi,
Are you working on any Z application or is it a standard one.
If it is a Z application, hope the problem persists in the performance of your application in regards with your business coding logic.
You can trace the performance of your webdynpro application by using the below stuffs.
Web Dynpro Trace Tool - Web Dynpro for ABAP - SAP Library
And also you can go ahead for the performance tuning.
Performance Tuning for SAP Web Dynpro ABAP - Web Dynpro ABAP - SCN Wiki
Please let me know which browser are you using ????
BR,
RAM.