I tried to compare the Intro from trunk and branch and got the following. Vincent?
JMarc /usr/lib/gcc/i586-mandriva-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/basic_string.h:709: typename _Alloc::rebind<_CharT>::other::reference std::basic_string<Char, Traits, Alloc>::operator[](typename _Alloc::rebind<_CharT>::other::size_type) [with _CharT = wchar_t, _Traits = std::char_traits<wchar_t>, _Alloc = std::allocator<wchar_t>]: Assertion '__pos < size()' failed. Program received signal SIGABRT, Aborted. [Switching to Thread -1239929952 (LWP 23373)] 0xbfffe410 in __kernel_vsyscall () Current language: auto; currently c (gdb) bt #0 0xbfffe410 in __kernel_vsyscall () #1 0xb71f9590 in raise () from /lib/i686/libc.so.6 #2 0xb71fae21 in abort () from /lib/i686/libc.so.6 #3 0x0808a937 in std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >::operator[] (this=0x9785644, __pos=19) at /usr/lib/gcc/i586-mandriva-linux-gnu/4.1.2/../../../../include/c++/4.1.2/debug/debug.h:58 #4 0x083323a2 in lyx::Paragraph::getChar (this=0x9765780, pos=19) at ../../lyx-devel/src/Paragraph.cpp:3003 #5 0x080bd00e in traverseSnake (p...@0xb6181f04, range=<value optimized out>, direction=lyx::Forward) at ../../lyx-devel/src/Compare.cpp:452 #6 0x080bfd6f in lyx::Compare::Impl::diff (this=0x974ed08, new_buf=0x92dc9e0, old_buf=0x96fefb0, dest_buf=0x976c3f0) at ../../lyx-devel/src/Compare.cpp:682 #7 0x080c04e3 in lyx::Compare::doCompare (this=0x974e6d8) at ../../lyx-devel/src/Compare.cpp:385 #8 0x080c054a in lyx::Compare::run (this=0x974e6d8) at ../../lyx-devel/src/Compare.cpp:375 #9 0xb764a6c9 in QAbstractItemModel::sort () from /usr/lib/qt4/lib/libQtCore.so.4 #10 0xb7604192 in start_thread () from /lib/i686/libpthread.so.0 #11 0xb729b90e in clone () from /lib/i686/libc.so.6