SYMPTOM:
A document with two datasets only displays results from one dataset when using dynamic text?
STEPS TO REPRODUCE:
1. Create two reports with filters
a. Attributes: Brand, Country, Year
Metrics: Profit, Revenue
Filter: Year=2010
b. Attributes: Country, Promotion Type, Year
Metrics: Profit, Revenue
Filter: Country=USA
2. Create a document with both datasets and add attributes and metrics as dynamic text


As is, the document returns results for only one of the datasets. Since both reports have similar attributes, either brand or promotion type will not display.
CAUSE:
A possible reason may be that one dataset, or both, have filters.
ACTION:
If one dataset, or both, have filters, then one has to be set as the primary dataset, and the other as the secondary for all the dynamic text to display.
Right click on either dataset and select as the secondary dataset.