Weird server crash

[yuriman]

Sometimes my garrysmod server crashes for unknown reason.
Please help me solve this problem
Heres the dmp file

Microsoft (R) Windows Debugger Version 6.12.0002.633 AMD64
Copyright (c) Microsoft Corporation. All rights reserved.


Loading Dump File [C:\Servers\Gmod\JailBreak\orangebox\dumps\crash_srcds.exe_20101201203858_1.dmp]
User Mini Dump File: Only registers, stack and portions of memory are available

Comment: 'Crash
Uptime( 1.729583 )

Memory
memusage( 52 % )
totalPhysical Mb(8190.36)
freePhysical Mb(3920.42)
totalPaging Mb(16378.86)
freePaging Mb(10421.09)
totalVirtualMem Mb(2047.88)
freeVirtualMem Mb(1640.41)
extendedVirtualFree Mb(0.00)

Paged Pool
prev PP PAGES: used: 0, free 0
final PP PAGES: used: 0, free 0
memallocfail? = 0
Active: inactive SpawnCount 0 MapLoad Count 0
Error count 0, end demo 0, abort count 0

ConVars (non-default)

var    value    default
sv_gamemode
    'Prisonbreak' 'sandbox'
sv_defaultgamemode
    'Prisonbreak' 'sandbox'
deathmatch
    '1' '0'
hostname
    'Garry's Mod' ''
sv_allow_voice_from_file
    '0' '1'
sv_timeout
    '180' '65'
r_flashlightdepthtexture
    '0' '1'
mat_motion_blur_enabled
    '0' '1'
joy_xcontroller_found
    '0' '1'

Console History (reversed)

28(1.716781):  Unknown command "sv_allow_wait_command"
27(1.715698):  maxplayers set to 32
26(0.769936):  [Nov  1 2010 15:56:15]
25(0.769268):  Garry's Mod server.dll Build #109 24(0.427365):  OK
23(0.426026):  Mounting zeno_clash.. 22(0.425309):  Failed
21(0.424060):  Mounting hl1mp.. 20(0.423588):  Failed
19(0.422269):  Mounting hl1.. 18(0.421657):  Failed
17(0.420433):  Mounting lostcoast.. 16(0.419916):  OK
15(0.418946):  Mounting portal.. 14(0.418455):  OK
13(0.417599):  Mounting hl2mp.. 12(0.416706):  Failed
11(0.415296):  Mounting episodic.. 10(0.414829):  OK
9(0.413867):  Mounting tf.. 8(0.413231):  Failed
7(0.412075):  Mounting ep2.. 6(0.411574):  Failed
5(0.410131):  Mounting dod.. 4(0.409547):  OK
3(0.408609):  Mounting cstrike.. 2(0.407136):  OK
1(0.405187):  Mounting hl2.. '
Symbol search path is: *** Invalid ***
****************************************************************************
* Symbol loading may be unreliable without a symbol search path.           *
* Use .symfix to have the debugger choose a symbol path.                   *
* After setting your symbol path, use .reload to refresh symbol locations. *
****************************************************************************
Executable search path is: 
Windows 7 Version 7600 MP (4 procs) Free x86 compatible
Product: Server, suite: TerminalServer SingleUserTS
Machine Name:
Debug session time: Wed Dec  1 20:38:59.000 2010 (UTC + 1:00)
System Uptime: not available
Process Uptime: 0 days 0:00:16.000
................................................................
...........................
This dump file has an exception of interest stored in it.
The stored exception information can be accessed via .ecxr.
(1c78.1bb8): Access violation - code c0000005 (first/second chance not available)
eax=00000000 ebx=00000000 ecx=00000000 edx=00000000 esi=00000368 edi=00000000
eip=774df861 esp=0018cb40 ebp=0018cbac iopl=0         nv up ei pl nz na po nc
cs=0023  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00000202
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for ntdll.dll - 
ntdll!ZwWaitForSingleObject+0x15:
774df861 83c404          add     esp,4