SVN integration works but SVN diff takes 74 seconds (ver 3.4.9)

Any idea why the SVN DIFF executed from within Bugtracker.NET takes (in general: can take) as long as 74 seconds?
The DIFF-operation was about a simple plain text file with about 50 lines of text and the difference was just 1-2 lines.
All other operations that can be done from BugTracker.NET perform as expected.

Environment and background info:

• Our SVN server (dedicated Linux server) and the server where the BugTracker.NET (virtual 64-bit Windows 2008 server) is running are themselves "fast".
• The base-version for our BugTracker.NET is 3.4.9.
• not related to question and not affecting the delay as this happens before the web-interface attempts to do the DIFF, but we are using abstraction layer between the SVN and BugTracker.NET and the SVN hook information is relayed to the BugTracker.NET from a Windows batch-file using svn.exe to get the commit log and then using CURL to do the HTTP POST to the BugTracker.NET's svn_hook.aspx