The assert subroutine failed ( file subversion/libsvn_delta/text_delta.c )

Hi,
I am facing the following issue when i try to sync master and mirror svn
repositories. Any idea how do i fix this.Is it svn 1.5 known bug? Please
help.

OS - AIX/Linux
SVN Version - 1.5
ERROR:
   - Failed to sync apd repos [ <mirror repository path>].
The assert subroutine failed: window->sview_len == 0 ||
(window->sview_offset >= ab->sbuf_offset && (window->sview_offset +
window->sview_len >= ab->sbuf_offset + ab->sbuf_len)
), file subversion/libsvn_delta/text_delta.c, line 609
/afs/awd/projects/eclipz/common/tools/bin/svnsync[30]: 11731186 IOT/Abort
trap(coredump)
Received on 2014-12-08 10:55:18 CET