I did a quick test and the viewer scroll bar is just fine for me. I'd like you to do two things for me:
1) Create a new web app, one line of code:
CrystalReportViewer1.ReportSource = <path to a report>
If the report has saved data it will just come, up, else it will prompt for a db logon. Doing a simple app like this, do you see the same issue?
2) If the above works, let me know the difference between the test app and you r app.
- Ludek