Does applying tempo effect nullify envelope effect?

Win 7 Home Premium Service Pack 1
Audacity 2.0.4 installed by .exe

Been puttering around with Audacity as a hobby, creating ringtones/soundbites from old pop tunes - having fun and learning quite a bit. But a couple of times, it has seemed like if the tempo effect was applied to a track in which the envelope tool had been used, the enveloping was reversed before the tempo was changed. Are the two incompatible? Or does tempo have to precede envelope? There was no warning the reversal would happen.

Thanks in advance…

Thanks, it is a known bug, mentioned in the Release Notes: (towards the bottom of that section).

Do Tracks > Mix and Render before the tempo effect.