Many people (myself included) have put this issue down to a plugin conflict, but this doesn't appear to be the case all the time.
The issue is, when some plugins are activated, the plugins page is cleared of all plugins (while the plugins still function as normal). The reason I'm becoming convinced it's more a bug than (at least always) a conflict, is because I made a point of activating a plugin I knew would cause this issue, and after setting its options to what I wanted, my blog (and all activated plugins) worked flawlessly. So how can it be a conflict when there is no actual conflict??
Can a developer (not a user...no offence, but even an enthusiast who keeps track of code changes can't be as sure of the answer as someone who actually worked on the project in depth) say if this is a permanent issue, where despite plugins having no ill-effect on the blog itself, still cause this pointless and excruciating inconvenient back-end issue?