diff --git a/netwerk/streamconv/converters/nsMultiMixedConv.cpp b/netwerk/streamconv/converters/nsMultiMixedConv.cpp
index 807abf050993..75304b50bfb4 100644
--- a/netwerk/streamconv/converters/nsMultiMixedConv.cpp
+++ b/netwerk/streamconv/converters/nsMultiMixedConv.cpp
@@ -453,6 +453,8 @@ nsMultiMixedConv::OnDataAvailable(nsIRequest *request, nsISupports *context,
             nsCRT::memcpy(tmp+mTokenLen+1, cursor, read);
             nsMemory::Free(buffer);
             buffer = tmp;
+            // need to reset cursor to the buffer again (bug 100595)
+            cursor = buffer;
         }
     }