powershell hangs when calling from bat file with redirected stdin

The build software we're using at work got upgraded this monday. After that, all all builds hanged on completion; powershell never exited.

Adding '-inputformat none' solved the issue, pending a software update from our build server supplier.

More information is available on these links
http://connect.microsoft.com/PowerShell/feedback/details/572313/powershell-exe-can-hang-if-stdin-is-redirected
http://stackoverflow.com/questions/4238192/running-powershell-from-msdeploy-runcommand-does-not-exit/4239192#4239192