We have recently noticed builds disappearing from the "Build History" listing on the project page. Developer was watching a build, waiting for it to complete and said it disappeared after it finished. Nothing was noted in any of the logs concerning that build.
The data was still present on the disk and doing a reload from disk brought the build back. We have other automated jobs that deploy these builds based on build number, so it is pretty big issue in our environment.
We are not able to reproduce at this point, but I still wanted to document what was happening.
I have seen other JIRA issues that look similar, but in those jobs were disappearing after a restart, or upgrade. That is not the case for us. The build disappears after completion, success or failure.