[@netweb Keymaster 13 years ago]

Try disabling all your plugins except bbPress, do you still see the issue?

Reenable each plugin one by one until you see the issue reappear.

Research the conflicting plugin for any one else having the same issue.

p.s. It is most likely the ‘Threaded Replies’ plugin at a guess as bbPress 2.4 includes ‘threaded replies’ in bbPress core.