Steps to reproduce:
1.Launch the mozilla 1.2.1_05 on redhat linux8.0 with jre1.4.2_b18.
2.Open http://sceri.prc.sun.com/vacationtool/vctl_request.jsp
3.Login then click button [<<] and press "check".
4.Mozilla crash

This bug can reproduce both on sparc solaris and pc linux.

Errors as following:
Exception in thread "Thread-3"
Unexpected Signal : 11 occurred at PC=0x402081C7
Function=(null)+0x402081C7
Library=/home/haojianwen/jdks/j2sdk1.4.2/jre/lib/i386/client/libjvm.so

NOTE: We are unable to locate the function name symbol for the error
      just occurred. Please refer to release documentation for possible
      reason and solutions.


Current Java thread:
        at sun.plugin.navig.motif.AThread.handleRequest(Native Method)
        at sun.plugin.navig.motif.AThread.JNIHandleLoop(AThread.java:35)
        at sun.plugin.navig.motif.AThread.run(AThread.java:27)

Dynamic libraries:
08048000-0804b000 r-xp 00000000 03:07 423523 /home/haojianwen/jdks/j2sdk1.4.
2/jre/bin/java_vm
0804b000-0804c000 rw-p 00002000 03:07 423523 /home/haojianwen/jdks/j2sdk1.4.
2/jre/bin/java_vm
40000000-40012000 r-xp 00000000 03:02 794992 /lib/ld-2.2.93.so
40012000-40013000 rw-p 00012000 03:02 794992 /lib/ld-2.2.93.so
40013000-4001b000 r-xp 00000000 03:07 1319340 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/native_threads/libhpi.so
4001b000-4001c000 rw-p 00007000 03:07 1319340 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/native_threads/libhpi.so
4001c000-40020000 rw-s 00000000 03:02 309232 /tmp/hsperfdata_haojianwen/1036
40020000-40023000 r--s 00000000 03:07 244345 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/ext/dnsns.jar
40023000-40030000 r-xp 00000000 03:02 48692 /lib/i686/libpthread-0.10.so
40030000-40033000 rw-p 0000d000 03:02 48692 /lib/i686/libpthread-0.10.so
40054000-40056000 r-xp 00000000 03:02 795005 /lib/libdl-2.2.93.so
40056000-40057000 rw-p 00001000 03:02 795005 /lib/libdl-2.2.93.so
40057000-40464000 r-xp 00000000 03:07 228057 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/client/libjvm.so
40464000-40480000 rw-p 0040c000 03:07 228057 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/client/libjvm.so
40492000-404a4000 r-xp 00000000 03:02 795009 /lib/libnsl-2.2.93.so
404a4000-404a5000 rw-p 00012000 03:02 795009 /lib/libnsl-2.2.93.so
404a7000-404c8000 r-xp 00000000 03:02 48690 /lib/i686/libm-2.2.93.so
404c8000-404c9000 rw-p 00021000 03:02 48690 /lib/i686/libm-2.2.93.so
404c9000-404d6000 r--s 00000000 03:07 244347 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/ext/ldapsec.jar
404d6000-404d7000 r-xp 00000000 03:02 1168224 /usr/X11R6/lib/X11/locale/commo
n/xlcUTF8Load.so.2
404d7000-404d8000 rw-p 00000000 03:02 1168224 /usr/X11R6/lib/X11/locale/commo
n/xlcUTF8Load.so.2
404d9000-404e2000 r-xp 00000000 03:02 795025 /lib/libnss_files-2.2.93.so
404e2000-404e3000 rw-p 00008000 03:02 795025 /lib/libnss_files-2.2.93.so
404e3000-404f3000 r-xp 00000000 03:07 1303063 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/libverify.so
404f3000-404f5000 rw-p 0000f000 03:07 1303063 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/libverify.so
4d706000 r-xp 00000000 03:02 1168222 /usr/X11R6/lib/X11/locale/commo
n/ximcp.so.2
4d706000-4d708000 rw-p 0001b000 03:02 1168222 /usr/X11R6/lib/X11/locale/commo
n/ximcp.so.2
4db91000-4dba1000 r-xp 00000000 03:07 1303069 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/libnet.so
4dba1000-4dba2000 rw-p 0000f000 03:07 1303069 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/libnet.so
4dba2000-4dbbd000 r-xp 00000000 03:07 1303073 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/libdcpr.so
4dbbd000-4dbd0000 rw-p 0001a000 03:07 1303073 /home/haojianwen/jdks/j2sdk1.4.
2/jre/lib/i386/libdcpr.so
4dca4000-4dd1a000 r--s 00000000 03:07 472407 /home/haojianwen/.java/deployme
nt/cache/javapi/v1.0/jar/jr_1.6.15.jar-f1a166e-1db7c111.zip
4dd35000-4dd40000 r-xp 00000000 03:02 795033 /lib/libnss_nisplus-2.2.93.so
4dd40000-4dd41000 rw-p 0000a000 03:02 795033 /lib/libnss_nisplus-2.2.93.so
4dd41000-4dd44000 r-xp 00000000 03:02 795022 /lib/libnss_dns-2.2.93.so
4dd44000-4dd45000 rw-p 00002000 03:02 795022 /lib/libnss_dns-2.2.93.so
4dd45000-4dd54000 r-xp 00000000 03:02 795037 /lib/libresolv-2.2.93.so
4dd54000-4dd55000 rw-p 0000e000 03:02 795037 /lib/libresolv-2.2.93.so

Heap at VM Abort:
Heap
 def new generation total 576K, used 188K [0x44910000, 0x449b0000, 0x44df0000)
  eden space 512K, 29% used [0x44910000, 0x449359a8, 0x44990000)
  from space 64K, 60% used [0x449a0000, 0x449a99a8, 0x449b0000)
  to space 64K, 0% used [0x44990000, 0x44990000, 0x449a0000)
 tenured generation total 2836K, used 2271K [0x44df0000, 0x450b5000, 0x4891000
0)
   the space 2836K, 80% used [0x44df0000, 0x45027cd8, 0x45027e00, 0x450b5000)
 compacting perm gen total 9728K, used 9574K [0x48910000, 0x49290000, 0x4c91000
0)
   the space 9728K, 98% used [0x48910000, 0x49269a60, 0x49269c00, 0x49290000)

Local Time = Tue Apr 1 09:34:59 2003
Elapsed Time = 73537
#
# HotSpot Virtual Machine Error : 11
# Error ID : 4F530E43505002EF
# Please report this error at
# http://java.sun.com/cgi-bin/bugreport.cgi
#
# Java VM: Java HotSpot(TM) Client VM (1.4.2-beta-b18 mixed mode)
#
# An error report file has been saved as hs_err_pid1036.log.
# Please refer to the file for further information.
#
INTERNAL ERROR on Browser End: Plugin instance index out of bounds -65

System error?:: Success