IIRF returns a 404 error code when a URL (with query parameters) exceeds 2048 characters
This issue has been commented on in previous issues (see comments in http://iirf.codeplex.com/WorkItem/View.aspx?WorkItemId=19175
I believe the way IIRF determines the maximum length to be incorrect.
1) long URL's work correctly when IIRF is not installed. Install IIRF and the it starts returning 404 errors.
2) The maximum length of URL's appears to be modifiable in registry setting http://support.microsoft.com/kb/820129
- where as IIRF uses an effectively hard-coded value.
I think the fact that a page/URL works without IIRF installed, then installing IIRF breaks functionality is an indication that this issue needs to be fixed.
This was all tested with IIS 6.0