Out of memory error in crystal reports

Hi,

We have created reports in Crystal reports 2008. The reports are sql bound and are shown in a .NET form using crystal report viwever 12. Some of our clients are complaining that after navigating few pages the report displays a big red X mark. Afterwards, no pages are diaplayed. Any other report loaded afterwards experinces the same issue. This is not specific to a report; the error occurs randomly in any of the reports. This does not happens all the times and is not reproducible always.

Can someone point me in right direction?

thanks,

Abhishek