All other functions works fine. Blame/Annotate, Checkout, RSS Feed, etc. Only show diff of selected revisions returns error message.

Error msg is like:
"""

An error occured

Missing @@ line before @@ -1,7 +1,7 @@ at line 5 of string

"""

If I run the "svn diff -r n:m" in the command line, it returns correct report. one example

"""
C:>svn diff -r 2:3
Index: myScript.js
===================================================================
--- myScript.js (revision 2)
+++ myScript.js (revision 3)
@@ -1,7 +1,7 @@

var customerLevel = "all";
var reportType = "PL"
-var defaultMonth = "FebFY07";
+var defaultMonth = "MarFY07";

"""


I am using SVN-WEB 0.53, Perl v5.8.8 built for MSWin32-x86-multi-thread, SVN 1.4.3, Windows 2003 + IIS 6.0

Any ideas why this error happened?