a build is already in progress

Hi all, with the latest alpha, remote build won't work:

2>System.InvalidOperationException: The operation cannot be completed because a build is already in progress.
2>   at Microsoft.Build.Shared.ErrorUtilities.ThrowInvalidOperation(String resourceName, Object[] args)
2>   at Microsoft.Build.Execution.BuildManager.BeginBuild(BuildParameters parameters)
2>   at Microsoft.Build.Execution.BuildManager.Build(BuildParameters parameters, BuildRequestData requestData)
2>   at Mono.IOS.VisualStudio.MonoTouchDeploySession.RemoteBuild(VSBuildServerClient server, Project project, IVsOutputWindowPane outputPane, MonoTouchProgressNotifier notifier)

I tryed reboot, uninstall/reinstall, ... A workaround ?