I had a feeling this was going to happen before long. I've been impotently watching a rusted line on the non-drive chainstay gradually increase in size over the last couple of months, checking every now and then to make sure it wasn't about to fall apart on me (or under me). Yesterday the crack was revealed to be the Grand Canyon. I'd planned to ride home 'gingerly', then got passed by a red light jumping Boardman, lost two minutes waiting, and chased him down...
Anyway, I'd been scouting about for a replacement frame anyway, so this will increase that effort. Will at Hubjub (where I got the frame) is a top bloke. I got a very apologetic reply from him (not his fault!) saying that Fixie Inc warranties are teeny-tiny short but they miiiiight do a deal on a new frame (would still be out of budget, and I like the idea of getting something older/mudguardable now anyway); he reckoned he might be able to do me a trade deal, but he's apparently struggling at the moment, which isn't nice to hear - I'll have to send some of my rebuild/newbuild cash his way.
He did say that normally he wouldn't expect to hear back from anyone at all with frame problems from ones he sells, but I think mine is the third Fixie Inc he sold that has then had 'issues'. And elsewhere someone commented that this was a 'Do Not Resuscitate' as basically the insides of the tubes hadn't been treated and would be utterly rotten, which apparently On-One had a problem with a while back.
The frame will get stripped, I'll use some of the more extreme measures required to get the seatpost shifted, now that I have nothing to lose, and I'll hang the frame in the garage until such time as the X is built, the new commuter is running and the Sunbeam is restored, then think about sending it off to get checked over and see if it's worth saving, or if the inside is a morasse of rust...