Memory error running data reports

Hi,
I currently have created 2 datareports. A very strange error occurs. When I run the first datareport based on request nos. it runs fine. When I then run the 2nd report based on dates it runs fine. But I have a memory issue when I run the 2nd report first and receive the error message in the attachment.
I have selected the cancel option on this screen and have received the following message.
"Unhandled exception in VB6.EXE (MYODBC3.DLL): 0xC0000005: Access Violation."
Any ideas?
Thanks.