Tasks broken in IU-98.231 Follow

There's something silly going on with the tasks support in the latest EAP. Suddenly, all but one of my changelists became detached from the previously associated task contexts. When I edit these changelists, "Track Context" check box is off, and there is no way to turn it on (it seems to be ignored). If I delete a changelist and create a new one from the same JIRA task, then it suddenly picks up the old context and works for a while, but then it may lose it again. Can't see any exceptions in the logs.

Has anybody else experienced this?