Don't panic. We've already done enough of that for everyone.
While inspecting the latest shipment of SP-445s, we found that many (in fact, almost all) of the film holders were "warped."
Heck, let's just do a video: Film holder Rev 3.
In case you skipped the video, here's the summary:
We had asked the factory to reduce the "flash" present on the previous batch of film holders. They said they could fix it by adjusting the pressure in the molding process. Turns out that was a bad idea.The change in pressure caused the film holders to warp.
We made two changes to fix the issue:
1. Added two vertical bars to help even out the pressure and plastic flow during molding.
2. Added more ejector pins to the mold. (These pins "pop" the part out after it's molded. You can see them in the video if you look fast.)
In the mean time, we've been inspecting and replacing film holders in all SP-445 kits before shipping. Fortunately, we had enough extra film holders from the previous run to tide us over.
The new film holders have arrived and have started shipping. If we screwed up and shipped you a warped one, just send us an email: firstname.lastname@example.org and we'll get it fixed.
Since people have asked about availability: Film holder Rev 3
However, if you're happy with your current film holders, there's no technical reason to "upgrade".