Hi Ken,
There are 2 parts to making a report.
a) looping through the tables, creating the WMF pages.
b) converting the WMF pages to a PDF file.
During the first part a NOOP instruction is sent to the browser to keep the connection alive. However during the PDF conversion it's not possible to do that. Basically any conversion that takes more than 30 seconds will cause a problem, if the report is not "progressed". (*) (Aside: The tracker converter is a lot faster than the SV one, so it can do bigger reports in 30 seconds, but there is a finite limit.)
(*) There are a variety of ways of calling, and presenting a report. In the earlier NetTalk versions it was limited to just calling the report procedure, usually sending the result to a different tab. However more recent NetTalk versions support a "Start" button, with a progress bar. The result of this can be in a new tab, or indeed inside the same existing page.
The newer approach (using a progress bar) does not suffer from any timeout and so supports reports of any size. (The progress bar will "pause" during the conversion to PDF, but the process completes correctly when done.) So if you are going to deal with large reports then I recommend using this approach.
see here in the docs;
http://www.capesoft.com/docs/NetTalk9/NetWebReports.htm#ReportProgressBarsCheers
Bruce