That's my guess, too. I know that both Eliezer and Robin posted there. Eliezer had definitely come to Robin's attention by 1999; he is cited in Robin's "Comments on Vinge's Singularity" page.
Of course, the most straightforward way to answer this question is to simply ask either of them.
Your guess and your evidence are both correct.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.