I've been using Reporting Services in a couple of projects and I like it many ways, but the product is not complete in it's functionality. One problem that we got stuck with for a while was that it is not possible to use Fields (data from data sources) in the Page Header. This is a big problem if you do things like invoices for example and I see it as a basic and very common needed feature. Luckily there is a work around.

After some googeling the first solution we did was to refer to a textbox in the page body. This seemed to work fine if you repeated the textbox with for example a table, but if the textbox is not part of a page, the value wouldn't be available for the header on that page. This meant that for some pages we had no invoice number and that is not satisfying. Back to Google and we found a suggested solution to use report parameters instead.

So what we did was adding report parameters for each field we wanted to display in the page header. The parameters value we choose to get from a field in a dataset. In the textboxes we refer to the parameters value and it works like a charm on each and every page. There are some issues to watch out for though. The first thing we did was to create a separate dataset for the page header, because when we used an existing dataset that also showed data in the body we got into problem with the fields in the body. We also had big problems with Visual Studio 2003 and the preview in the report designer. It did not work at all when using this solution, but the deployed report works just fine. This makes it harder to develop the report though, so my only suggestion is to do the page header last or upgrade to SQL Server 2005. In SQL Server 2005 also the designer works perfectly and a great new feature  is the possibility to hide these parameters from the user so they won't get prompted for values. The overall feeling of Reporting Services in SQL Server 2005 is that it is a little bit more polished and as I see it is the first version. Still there are missing features and a lot of things that can be improved, but I'm ready to do a lot to get rid of the more mature Crystal Reports, because of all the problems it still have (even though they are on version 11 or something).