Rob, does your solution bring up every thread or only ones within a specified time frame? I thought there was a limit to how far back that would go.
Geeza, I just go to my own profile and click "Find latest started threads". If you know the approximate time you made the thread it's pretty easy to find
You're limited to 10 pages of results, so depending on how many threads the user has made, it may not be possible to list every thread. In the case of The_Geeza, yes - every thread was listed.
If you narrow down your search criteria, it will yield less results so you are more likely to get what you want.
Add the username, then change the option to "Find threads started by user".
Under Find Posts - "A Year Ago" AND "Older"
Here is a screenshot of a search I just did, to demonstrate just how far back you can search.