Working with Reporting Services is sometimes like practicing black magic....

I'm working on some reports for Team Foundation Server, to be used in our software factory Endeavour. We are using SQL Reporting Services to produce these reports.

During this, I run into all kinds of  'interesting' behaviour of Visual Studio 2005.

For instance, I once in a while get this error message while performing a preview of the report:

An error occurred during local report processing.
The definition of the report '/ABC' is invalid.
The report parameter 'XYZ' uses the field 'ParameterValue' in a data set reference, but the data set 'XYZ' does not contain that field.

So how to fix this. In my case, the data set does in fact contain the correct fields. It turns out that going to the Data tab, selecting the 'XYZ' dataset and re-executing the query for that dataset succesfully, fixes the error. Mind you, I have not touched any code or definitions at this point!

Is there any logic behind this? I'm trying to keep myself going with the idea: "it fixed the problem, do not worry why".. but actually that's hard for me, because I always want to know “Why does this happen”