On RH 9.0, using gcc 3.2.2, I invoked valgrind with the command line:
/opt/lcl/bin/valgrind --tool=memcheck --gen-suppressions=yes \
-v --db-attach=yes <my_program>

When valgrind detected an error, it tried to start gdb and got the assertion
failure:

==8753==
==8753== Mismatched free() / delete / delete []
==8753==    at 0x3C01E829: operator delete(void*) (vg_replace_malloc.c:129)
==8753==    by 0x3C6E881A: RTF_Display::ColorBar::setTbl(RTF_GL::GLColorTbl*,
char const*, char**, int) (ColorBar.cc:67)
==8753==    by 0x3C6EB041:
RTF_QT::QtColorBar::changeTblSlot(RTF_GL::GLColorTbl*, char const*, char**, int)
(QtColorBar.hh:73)
==8753==    by 0x3C6EAB87: RTF_QT::QtColorBar::qt_invoke(int, QUObject*)
(moc_QtColorBar.cc:131)
==8753==  Address 0x3D2472FC is 0 bytes inside a block of size 544 alloc'd
==8753==    at 0x3C01E5C0: operator new[](unsigned) (vg_replace_malloc.c:113)
==8753==    by 0x3C6E8854: RTF_Display::ColorBar::setTbl(RTF_GL::GLColorTbl*,
char const*, char**, int) (ColorBar.cc:73)
==8753==    by 0x3C6EB041:
RTF_QT::QtColorBar::changeTblSlot(RTF_GL::GLColorTbl*, char const*, char**, int)
(QtColorBar.hh:73)
==8753==    by 0x3C6EAB87: RTF_QT::QtColorBar::qt_invoke(int, QUObject*)
(moc_QtColorBar.cc:131)
==8753==
==8753== ---- Attach to debugger ? --- [Return/N/n/Y/y/C/c] ---- y
starting debugger
==8753== starting debugger with cmd: /h/atd/vanandel/bin/Linux/gdb -nw
/proc/8759/fd/822 8759

valgrind: vg_signals.c:1587 (vg_sync_signalhandler): Assertion `info->si_code <=
0' failed.
==8759==    at 0xB8029F95: vgPlain_skin_assert_fail (vg_mylibc.c:1211)
==8759==    by 0xB8029F94: assert_fail (vg_mylibc.c:1207)
==8759==    by 0xB8029FD2: vgPlain_core_assert_fail (vg_mylibc.c:1218)
==8759==    by 0xB802F61A: vg_sync_signalhandler (vg_signals.c:1630)

sched status:

Thread 1: status = Runnable, associated_mx = 0x0, associated_cv = 0x0
==8759==    at 0x3C01E829: operator delete(void*) (vg_replace_malloc.c:129)
==8759==    by 0x3C6E881A: RTF_Display::ColorBar::setTbl(RTF_GL::GLColorTbl*,
char const*, char**, int) (ColorBar.cc:67)
==8759==    by 0x3C6EB041:
RTF_QT::QtColorBar::changeTblSlot(RTF_GL::GLColorTbl*, char const*, char**, int)
(QtColorBar.hh:73)
==8759==    by 0x3C6EAB87: RTF_QT::QtColorBar::qt_invoke(int, QUObject*)
(moc_QtColorBar.cc:131)


Note: see also the FAQ.txt in the source distribution.
It contains workarounds to several common problems.

If that doesn't help, please report this bug to: valgrind.kde.org

In the bug report, send all the above text, the valgrind
version, and what Linux distro you are using.  Thanks.