Mail app crash: indexing in 10.3.9, importing in 10.4.10

[kls1013]

I'm running an iMac G4. Mail is crashing on start-up consistently, and under both 10.3.9 and 10.4.10. I’ve tried every suggestion (detailed below) that I’ve found on multiple forums, and am desperate for new ideas.

Background:
Mail started crashing on startup under 10.3.9 about 2 weeks ago. I could see the mailboxes and messages, but could not access them while it took a long time setting up the Address Book.
Then I’d see a message saying it was indexing the email messages – and it would crash while indexing the same specific message (#95 in the Inbox) every time.

I tried each of the following separately, and did a ReStart after each one, with no improvement:

1) Moved Library/Caches/com.apple.ATS to Trash
2) Moved /Library/Caches/Mail to Trash
3) Moved Library/Preferences/com.apple.mail.plist” to Trash
4) Moved message.plist to Trash
5) Moved MessageSorting.plist to Trash
6) Moved MessageSortng.plist.backupto Trash
7) Moved LSMMAP and LSMMAP2 to Trash
8) Moved Library/preferences/Qtime.pref to Trash
9) Repaired permissions
10) Did a re-install and archive of 10.3.9

Just to make things more complicated, I just upgraded to 10.4.10, and when the new version of Mail attempts to import email from the old version, it crashes on startup while indexing the same message – now referred to as #690 in the Inbox.

I tried each of the following separately under 10.4.10, and did a ReStart after each one, with no improvement:

1) Moved Library/Caches/com.apple.ATS to Trash
2) Moved Library/Caches/com.apple.addressbook to Trash

Here’s what I think is the relevant part of the crash log from the 10.4.10 version. Can anyone decipher this for me or make any suggestions at all?
I’d really appreciate it.

Exception: EXC_BAD_ACCESS (0x0001)
Code[0]: 0x0000000a
Code[1]: 0x04e19000


Thread 2 Crashed:
0 libSystem.B.dylib 0x90036adc regexec + 428
1 com.apple.MessageFramework 0x9b1bd8dc -[RegularExpression matchedRangeForCString:range:subexpressionRanges:count:] + 324
2 com.apple.MessageFramework 0x9b2a01c0 _mungeFromSpace + 344
3 com.apple.MessageFramework 0x9b2a03a4 -[NSData(NSDataUtils) unquotedFromSpaceDataWithRange:] + 60
4 com.apple.MessageFramework 0x9b263b88 -[NeXTMbox _fetchBodyDataForMessage:andHeaderDataIfReadilyAvailable:] + 464
5 com.apple.MessageFramework 0x9b1ef7f0 -[MessageStore bodyDataForMessage:] + 100
6 com.apple.MessageFramework 0x9b235104 -[Message messageDataIncludingFromSpace:] + 72
7 com.apple.MessageFramework 0x9b22b1ac +[Library addMessages:withMailbox:fetchBodies:isInitialImportldMessagesByNewMessage:] + 1496
8 com.apple.MessageFramework 0x9b2c3630 +[Library importMailbox:] + 580
9 com.apple.MessageFramework 0x9b2c4050 +[Library importEverythingIncludingDisabledAccounts:] + 2460
10 com.apple.mail 0x0012f530 0x1000 + 1238320
11 libobjc.A.dylib 0x909221f4 objc_msgSendv + 180
12 com.apple.Foundation 0x90afec94 -[NSInvocation invoke] + 944
13 com.apple.MessageFramework 0x9b1cb800 -[MonitoredInvocation invoke] + 144
14 com.apple.MessageFramework 0x9b1cb67c +[WorkerThread _execute:] + 76
15 com.apple.Foundation 0x90b031a0 forkThreadForFunction + 108
16 libSystem.B.dylib 0x9002bd08 _pthread_body + 96

Thread 2 crashed with PPC Thread State 64