Tomcat stops with EXCEPTION_ACCESS_VIOLATION (0xc0000005)

Hello,

We are using BusinessObjects 4.0. Sometimes our tomcat stops with the following message in stdout.log

# A fatal error has been detected by the Java Runtime Environment:

#

#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000000006d8734ea, pid=8548, tid=2716

#

# JRE version: 6.0_37-b06

# Java VM: Java HotSpot(TM) 64-Bit Server VM (20.12-b01 mixed mode windows-amd64 compressed oops)

# Problematic frame:

# C  [zip.dll+0x34ea]

#

---------------  T H R E A D  ---------------

Current thread (0x000000000bdec000):  JavaThread "http-80-32" daemon [_thread_in_native, id=2716, stack(0x0000000019570000,0x0000000019670000)]

siginfo: ExceptionCode=0xc0000005, reading address 0x000000000750b000

I have to start it and then it works fine.

Any idea what the error could mean?

thanks!