Summary:

If you set notification display count to 30 we are unable to scroll through the list of notifications.

Solution:
This issue is related to overflow field which is located in ergonomic.css in line 1838.
Original code looks like this:
body { background: #fff; color: #000; margin: 0; overflow: hidden auto; font: 400 13px Arial,Helvetica,sans-serif;
}
Parameter hidden is causing this issue.
Please try to edit ergonomic.css by deleting hidden parameter and leave it with auto:
body { background: #fff; color: #000; margin: 0; overflow: auto; font: 400 13px Arial,Helvetica,sans-serif;
}
File is located in C:\Program Files (x86)\Sage\CRM\CRMSP2\WWWRoot\Themes
After this delete temporary files and try again.