Sounds like you are using the report wizard.  The wizards have limits that
are less than the actual limits.

Try building your report with just some of the fields that you need.  Once
you've done that you can go into the reports design view and add additional
controls.  The easiest way to do that is to use the Fields window and drag
from there to the appropriate section of the report

Tip: Select View: Field List from the menu to see the list of fields
available for the report.