The TP might work at some time and then fail at another time, and this independently of the viewer is use. To compare, you must do the *same* TPs (same sim, same time, same number of avatars in departure and arrival sims, same attachments worn) several times. You'll then notice the same failure frequency.
Again, this is *NOT* a viewer issue, and FYI, no code even remotely touching the TP was modified in the last versions of the viewer.