sink_input_pop_cb() in module-virtual-sink copies samples assuming that the format is float32ne, but the user can configure a different format. To keep things simple, the float32ne assumption is probably a good one, so the solution is then to prevent the user from configuring the sample format.
I am working on this.
Fixed in my "next" branch: https://gitorious.org/~tanuk/pulseaudio/tanuk-clone/commit/109a89d3189130ac9ab552138179fa1cfc83240b
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.