From rmcauliffe :
I attended the Sno-Core 98 concert on 2/25/98 at Sokol Hall in Omaha, Nebraska. It was a great concert.
I think Primus started the concert off, followed by The Aquabats, and then Blink-182. I remember Tom DeLonge walking through the crowd before they played right by us. It was great because it was still before Blink-182 really got huge with their "Enema Of The State" album.
I was introduced (by a friend that I went to the concert with) to The Aquabats' "Fury Of..." a few months before so we both knew a bit about the band. And we were both big fans of Blink-182. We knew Scott Raynor was their drummer. However, after The Aquabats played we definitely saw Travis Barker take off the mask and whatnot and began warming up (and then playing the concert) for Blink-182. We thought that is was weird but didn't really put it together until a few months later when it was revealed that Scott was fired from the band.
Did we see the first performance of Travis with Blink-182?
Here's where I noticed something that kind of backs it up. Sounds like there was an argument at that actual show.