Do not worry.  I do not think your DNN instance is unsalvageable.  There is a configuration in the newer version web.config that allows you to set (and allows DNN to search) for the object qualifier for database objects.  This is your problem.

The default for all objects is now set to dnn_.  This in effect causes DNN to search for all DB objects with the naming convention of dnn_XYZ.  (ex.  dnn_GetPortals)

SOLUTION:  Look for the folllowing in your web.config:

objectQualifier="dnn_"

simply remove the dnn_  value (thus blanking out the object qualifier).

Hope this helps!

Jason Kergosien
Ingen Systems