SharePoint 2010 site with PerformancePoint issues

I have a site where I have performed a classic Detach-Attach to a new server with SP2010.

Everything else works fine, except the PerformancePoint items.

I am totally new to PerformancePoint, Reporting Services and DataWarehouse and need some help.

Currently the new site gives me error 40986 when connecting to the existing dashboards. Some of the WebParts also display: 'You do not have permission to view this data.'

PerformancePoint Configuration and the Secure Store with new Keys generated have been done.

I have read up about some suggestions that I will need PerformancePoint Dashboard Designer to Import these 'sites'

Could somebody provide me with a set of instructions or suggested site where I could get some more information?

Is there a structured sequence I need to follow?

Many thanks in advance!