Lookout 6.5 critical crash - writes to random modbus addresses

Question

Hello,
We are experiencing a rather critical problem with Lookout 6.5. The proces file contains approximately 148 Modbus/TCP connections, some overview panels, a properties panel which uses a symbolic link to retrieve properties from a certain modbus object.
Seemingly random, Lookout crashes during operation (with the Windows send/don't send window). When this happens, the second before the crash actually occurs Lookout starts writing seemingly random values to addresses to all the modbus devices. Some to addresses which are connected in Lookout, and to some that are not (even to addresses that actually don't exist on the device, which causes it to return an exception). The addresses do seem to be in an increasing sequence (i.e. it starts at 500, then starts writing further until about 850). Values I've seen are mostly 0, but also 256, 2308, 512, 2048, 3844.
I've attached a packet capture log which shows the write commands Lookout is sending.
Does anyone have any idea what could cause this crash or things I can check?
Attachments:
dump.txt ‏175 KB

Answer 1

Also uploaded a second dump file as Randomwritecrash2.zip - I'll keep uploading dump files in sequence.
Crash data from this dump:
(1328.bd4): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=01cbcd1a ebx=00f70000 ecx=3e720012 edx=3e720013 esi=00f70838 edi=00000009
eip=7c902a9d esp=0013f4f4 ebp=00f70838 iopl=0         nv up ei pl nz na po nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010202
ntdll!tan+0xcf:
7c902a9d 8b18            mov     ebx,dword ptr [eax]  ds:0023:01cbcd1a=????????
0:000> kb
ChildEBP RetAddr  Args to Child              
WARNING: Stack unwind information not available. Following frames may be wrong.
0013f4f8 7c91020e 00000009 00f70838 00f70000 ntdll!tan+0xcf
0013f510 7c9101db 0013f744 7c90e920 7c910228 ntdll!RtlAllocateHeap+0x14a
0013f528 7c91019b 00f70838 00000013 0000003f ntdll!RtlAllocateHeap+0x117
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for C:\WINDOWS\system32\MSVCR71.dll - 
0013f754 7c3416b3 00f70000 00000000 0000003f ntdll!RtlAllocateHeap+0xd7
0013f794 7c3416db 0000003f 7c3416f8 0000003f MSVCR71!_crtLCMapStringA+0x305
00000000 00000000 00000000 00000000 00000000 MSVCR71!_crtLCMapStringA+0x32d