Mail always crashes on startup

Question

Every time I try to launch Mail it crashes. I've tried restarting, running disk utility to verify permissions, ensuring I have the latest software updates. I have a good network connection ( I can launch Safari). I get the crash even when disconnected from the network.
This just started happening yesterday. One suspicious thing is that the most current mail is from a business, and had images that were hidden at first. I clicked the button "show all images in this mail" (or something like that) and it seemed fine (showed the images), but I think that the next time I launched Mail was when the crashing started. When Mail opens, I can briefly see the inbox and the potentially problem eMail, before I get the error (pasted below).
thanks for any advice,
Kevin
error report:
"The application Mail quit unexpectedly"
Date/Time: 2006-01-13 11:41:44.776 -0800
OS Version: 10.4.4 (Build 8G32)
Report Version: 3
Command: Mail
Path: /Applications/Mail.app/Contents/MacOS/Mail
Parent: WindowServer [54]
Version: 2.0.5 (746)
Build Version: 2
Project Name: MailViewer
Source Version: 7460000
PID: 184
Thread: 0
Exception: EXCBADACCESS (0x0001)
Codes: KERNPROTECTIONFAILURE (0x0002) at 0x00018038
<snip>
(lots of info about threads....)
</snip>
G5   Mac OS X (10.4.4)  

Answer 1

I am at a loss. Mail is behaving very similarly to what others have experienced. My iBook (owned by my university) was recently upgraded to Tiger by our tech staff. I do not know what procedure they used to do this.
It has seemed to work fine since the conversion; all the mailboxes were imported properly. All functions worked fine. I could send and receive messages without difficulty. Yesterday I installed the latest 10.4.4 upgrade. Again, no apparent problems until I tried to read a message. (Mail is set to not automatically load images.) It crashed and has continued to crash every time I try to open it.
Here is what I've tried. These are based on a careful reading of this (and other) message thread(s).
-I've run Disk Utility several times, both before and after the following actions.
-I've dragged Mail off the dock and have tried to launch Mail directly from the OSX applications folder.
-I've tried holding down the shift key while launching Mail. The shift key strategy does not seem to help. The message I was trying to read slowly appears regardless of whether the shift (or command) key is held down. Mail is then unresponsive to attempts to double click the bar between the mail list (to get rid of the preview pane) and then crashes.
-I've deleted the MessageUidsAlreadyDownloaded files
-Per Apple's suggestions in the following KB page (http://docs.info.apple.com/article.html?artnum=301315), I've deleted mbox (which is a file, not a folder), tableofcontents, mbox.SKindex, Info.plist (but not Info.plist that's in the Mailboxes folder), mbox.SKindex.isValid, content_index, & content_index-(your computer name)-Computer.local files in my home-Library-mail folders.
-I do have two extra copies of Mail. One is located in the Previous Systems folder. I assume this was created as part of the archive process when Tiger was installed. I have not deleted it yet. Nor have I deleted the OS9 version of Mail. (I never need the OS9 applications, but don't want to start secondary problems by deleting them.)
-I've searched for the Helvetica.dfont. There are three copies. One is located in System/Library/Fonts. A second is located in the Previous Systems folder system. The third is located in Users/Shared/Font Reserve Database/Vault/dfont/Apple Computer/Helvetica/4.0/. I have wondered whether I should delete this whole Font Reserve set of folders (it is not used). There were problems with its installation, however, I have been using the "if it's not broken, don't fix it" maxim.
Any help on this will be greatly appreciated.
iBook dual USB   Mac OS X (10.4.4)  
iBook dual USB   Mac OS X (10.3.9)