IChat crashes with EXC_BAD_ACCESS (SIGBUS) when attempting screen sharing

Question

I seem to have an unstable iChat on my 27 inch i7 iMac since early January when it replaced a 24 inch model where iChat worked well.
I've been reading various helpful posts and tried things like trashing the plists, set my speed limit to 500kbps, running in 32 bit mode.
I use screen sharing to support my elderly mother and some of her equally elderly friends who I have converted to mac but it's getting terribly frustrating since I cannot reliably connect for screen sharing and end up having to drive for 2 hours to sort out basic stuff. The most recent crash is EXCBADACCESS (SIGBUS). I'll post a short extract below. But I've also had other errors (SIGSEGV).
I've now discovered that I get the same failure about half the time when testing in-house both connecting over the internet and via Bonjour to a new 15 inch core duo MBP both machines running 10.6.2. Any ideas please? Sometimes it works, sometimes it doesn't.
Process: iChat [735]
Path: /Applications/iChat.app/Contents/MacOS/iChat
Identifier: com.apple.iChat
Version: 5.0.1 (743)
Build Info: iChat-7430000~2
Code Type: X86 (Native)
Parent Process: launchd [89]
Date/Time: 2010-02-28 18:59:06.521 +0000
OS Version: Mac OS X 10.6.2 (10C2234)
Report Version: 6
Interval Since Last Report: 1278114 sec
Crashes Since Last Report: 24
Per-App Interval Since Last Report: 863061 sec
Per-App Crashes Since Last Report: 22
Anonymous UUID: 890F0781-E477-4575-9FB1-C9DCD4D8B331
Exception Type: EXCBADACCESS (SIGBUS)
Exception Codes: KERNPROTECTIONFAILURE at 0x0000000000000021
Crashed Thread: 11
Thread 11 Crashed:
0 libobjc.A.dylib 0x97083ed7 objc_msgSend + 23
1 com.apple.CoreFoundation 0x96ba5fc2 __CFBasicHashAddValue + 50
2 com.apple.CoreFoundation 0x96bae699 CFBasicHashSetValue + 169
3 com.apple.CoreFoundation 0x96bae49a CFDictionarySetValue + 202
4 com.apple.Foundation 0x91e3f87a -[NSCFDictionary setObject:forKey:] + 308
5 com.apple.viceroy.framework 0x94d76046 -[SDPAnalyzer resetSDP] + 214
6 com.apple.viceroy.framework 0x94d781f5 -[SDPAnalyzer init] + 117
7 com.apple.viceroy.framework 0x94d76e42 -[SDPAnalyzer initWithViceroyDefaultsUsingZeroes:forAudioOnly:withUserCount:] + 50
8 com.apple.viceroy.framework 0x94da6d0a -[VideoConferenceMultiController(VCInitiateConference_Private) initiateConferenceCallUsingConnectionDataWithErrorInfoToUser:withRemoteVCConnec tionData:withLocalVCConnectionData:oneWayOnly:errorInfo:shouldFindExternalIP:] + 1034
9 com.apple.viceroy.framework 0x94da52ef -[VideoConferenceMultiController(VCInitiateConference_Private) initiateConferenceToUserWithVCConnectionDataProc:] + 927
10 com.apple.Foundation 0x91e528d8 -[NSThread main] + 45
11 com.apple.Foundation 0x91e52888 _NSThread__main_ + 1499
12 libSystem.B.dylib 0x92253fbd pthreadstart + 345
13 libSystem.B.dylib 0x92253e42 thread_start + 34

Answer 1

Hi,
It does seem that is a specific build.
10C refers to 10.6.2 as a range of builds
The numbers after that are normally 3 digits long and yours is 4
Those people that sign up for the Developers copies tend to get minor/text update as testers along the way which is why a General Release version tends to be a specific number. (In this case 10C540)
There are other things we could try that may help.
Try Launching Disk Utility (Applications/Utilities and Setting the tab to First Aid then use the "Repair Permissions" button.
Also try a PRAM reset.
Shut down the computer.
Restart it holding down APPLE(or ⌘)ALT(⌥)+PR Keys until you have heard three Start Up Bongs.
Do them one at a time and then test iChat.
After this we will move to deleting ichat .plists and forcing it to rewrite them from defaults.
9:12 PM Sunday; February 28, 2010
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"