Crash when running WebEx on remote desktop

When running WebEx (www.webex.com) on Windows XP Media Center Edition, rdesktop crashes with the following output:

*** glibc detected *** rdesktop: double free or corruption (fasttop): 0x083dac10 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0xb7c717cd]
/lib/tls/i686/cmov/libc.so.6(cfree+0x90)[0xb7c74e30]
/usr/lib/libX11.so.6(XFree+0x1d)[0xb7d87dbd]
rdesktop[0x805c606]
rdesktop[0x805718d]
rdesktop[0x805dcd3]
rdesktop[0x805df38]
rdesktop[0x805e098]
rdesktop[0x805e64d]
rdesktop[0x805f14b]
rdesktop[0x8060cd2]
rdesktop[0x80612e8]
rdesktop[0x8061f3c]
rdesktop[0x804db07]
/lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xdc)[0xb7c1febc]
rdesktop[0x804bd21]
======= Memory map: ========
08048000-08074000 r-xp 00000000 08:04 13228358 /usr/bin/rdesktop
08074000-08076000 rw-p 0002b000 08:04 13228358 /usr/bin/rdesktop
08076000-08438000 rw-p 08076000 00:00 0 [heap]
b7900000-b7921000 rw-p b7900000 00:00 0
b7921000-b7a00000 ---p b7921000 00:00 0
b7a9c000-b7aa7000 r-xp 00000000 08:04 163902 /lib/libgcc_s.so.1
b7aa7000-b7aa8000 rw-p 0000a000 08:04 163902 /lib/libgcc_s.so.1
b7aa8000-b7aac000 r-xp 00000000 08:04 13223585 /usr/lib/libXfixes.so.3.1.0
b7aac000-b7aad000 rw-p 00003000 08:04 13223585 /usr/lib/libXfixes.so.3.1.0
b7aad000-b7ab4000 r-xp 00000000 08:04 13223605 /usr/lib/libXrender.so.1.3.0
b7ab4000-b7ab5000 rw-p 00006000 08:04 13223605 /usr/lib/libXrender.so.1.3.0
b7ab5000-b7abd000 r-xp 00000000 08:04 13223577 /usr/lib/libXcursor.so.1.0.2
b7abd000-b7abe000 rw-p 00007000 08:04 13223577 /usr/lib/libXcursor.so.1.0.2
b7ad2000-b7ad4000 r-xp 00000000 08:04 13225298 /usr/lib/gconv/UTF-16.so
b7ad4000-b7ad6000 rw-p 00001000 08:04 13225298 /usr/lib/gconv/UTF-16.so
b7ad6000-b7b11000 r--p 00000000 08:04 13304196 /usr/lib/locale/en_US.utf8/LC_CTYPE
b7b11000-b7be8000 r--p 00000000 08:04 13304195 /usr/lib/locale/en_US.utf8/LC_COLLATE
b7be8000-b7bea000 rw-p b7be8000 00:00 0
b7bea000-b7bee000 r-xp 00000000 08:04 13223581 /usr/lib/libXdmcp.so.6.0.0
b7bee000-b7bef000 rw-p 00003000 08:04 13223581 /usr/lib/libXdmcp.so.6.0.0
b7bef000-b7bf1000 r-xp 00000000 08:04 13223570 /usr/lib/libXau.so.6.0.0
b7bf1000-b7bf2000 rw-p 00001000 08:04 13223570 /usr/lib/libXau.so.6.0.0
b7bf2000-b7c05000 r-xp 00000000 08:04 13224543 /usr/lib/libz.so.1.2.3
b7c05000-b7c06000 rw-p 00012000 08:04 13224543 /usr/lib/libz.so.1.2.3
b7c06000-b7c08000 r-xp 00000000 08:04 167141 /lib/tls/i686/cmov/libdl-2.5.so
b7c08000-b7c0a000 rw-p 00001000 08:04 167141 /lib/tls/i686/cmov/libdl-2.5.so
b7c0a000-b7d45000 r-xp 00000000 08:04 167135 /lib/tls/i686/cmov/libc-2.5.so
b7d45000-b7d46000 r--p 0013b000 08:04 167135 /lib/tls/i686/cmov/libc-2.5.so
b7d46000-b7d48000 rw-p 0013c000 08:04 167135 /lib/tls/i686/cmov/libc-2.5.so
b7d48000-b7d4c000 rw-p b7d48000 00:00 0
b7d4c000-b7e39000 r-xp 00000000 08:04 13223566 /usr/lib/libX11.so.6.2.0
b7e39000-b7e3d000 rw-p 000ed000 08:04 13223566 /usr/lib/libX11.so.6.2.0
b7e3d000-b7f67000 r-xp 00000000 08:04 13225703 /usr/lib/i686/cmov/libcrypto.so.0.9.8
b7f67000-b7f7b000 rw-p 00129000 08:04 13225703 /usr/lib/i686/cmov/libcrypto.so.0.9.8
b7f7b000-b7f7f000 rw-p b7f7b000 00:00 0
b7f82000-b7f83000 r--p 00000000 08:04 13304201 /usr/lib/locale/en_US.utf8/LC_NUMERIC
b7f83000-b7f84000 r--p 00000000 08:04 13304204 /usr/lib/locale/en_US.utf8/LC_TIME
b7f84000-b7f85000 r--p 00000000 08:04 13304199 /usr/lib/locale/en_US.utf8/LC_MONETARY
b7f85000-b7f86000 r--p 00000000 08:04 13304205 /usr/lib/locale/en_US.utf8/LC_MESSAGES/SYS_LC_MESSAGES
b7f86000-b7f87000 r--p 00000000 08:04 13304202 /usr/lib/locale/en_US.utf8/LC_PAPER
b7f87000-b7f88000 r--p 00000000 08:04 13304200 /usr/lib/locale/en_US.utf8/LC_NAME
b7f88000-b7f89000 r--p 00000000 08:04 13304194 /usr/lib/locale/en_US.utf8/LC_ADDRESS
b7f89000-b7f8a000 r--p 00000000 08:04 13304203 /usr/lib/locale/en_US.utf8/LC_TELEPHONE
b7f8a000-b7f8b000 r--p 00000000 08:04 13304198 /usr/lib/locale/en_US.utf8/LC_MEASUREMENT
b7f8b000-b7f92000 r--s 00000000 08:04 13225303 /usr/lib/gconv/gconv-modules.cache
b7f92000-b7f93000 r--p 00000000 08:04 13304197 /usr/lib/locale/en_US.utf8/LC_IDENTIFICATION
b7f93000-b7f95000 rw-p b7f93000 00:00 0
b7f95000-b7fae000 r-xp 00000000 08:04 163861 /lib/ld-2.5.so
b7fae000-b7fb0000 rw-p 00019000 08:04 163861 /lib/ld-2.5.so
bf95e000-bf973000 rw-p bf95e000 00:00 0 [stack]
ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
Aborted (core dumped)

rdesktop is running from a console on kubuntu 7.04 (feisty), kde version 3.57, X.org version 7.2.0