You're in luck, I fixed this myself. Apple suck for support, had nothing but problems from them.
I downloaded a tool called "iBackupBot" and connected my phone to my PC. It will detect the phone and load up a rather long list of files.
You need to find the default template for text messages (Sorry i can't be more specific its been a while!) and you can right click it and edit it as a text file. Delete the annoying text between the lines where it is quoted.
Leave the other code in as it's important (If there is any)
Hope this helps you.
Thank you Wedge!
Here it goes -
1) Download iBackupBot: http://download.cnet.com/iBackupBot/3000-2141_4-10969873.html
2) Plug phone into computer and run backup
3) Use "Explorer" box to find Messages: HomeDomain/Library/SMS/Drafts/(null).draft/
4) In "Null Drafts" there is a file "message.plist"
5) Double click to open, (cancel the popup if you did not purchase the iBackupBot) and you will see the prepopulating message on the <string> line 6
6) Delete the offending text, leave all code
7) Close text editor
8) Right click on message.plist file and select "Restore selected item(s) to device"
9) File will be restored to your phone and it will restart itself.
10) Voila! Now it is time to consider that Windows phone....:)