Failed to download buildpack cache

[insanitysauce]

I'm pushing a .NET MVC4 app (pretty vanilla app, just file --> new project --> MVC4 and build). When I try this:

 cf push mvcmovie --path . --stack mswin-clr

I get this in the stdout:

Uploading mvcmovie... OK
Preparing to start mvcmovie... OK
Checking status of app 'mvcmovie'...............................................................Push unsuccessful.

The dea_ng.log has this:

{"timestamp":1381935342.919931,"message":"Failed to download buildpack cache from http://stage_user:password@10.10.10.112:9022/staging/buildpack_cache/42b2c2b0-dd37-4638-b372-c26dda9924e2/download","log_level":"error",
"source":"Staging","data":{"app_guid":"42b2c2b0-dd37-4638-b372-c26dda9924e2","task_id":"744ed1321a2512a64fd0fa24e3df1644"},"thread_id":7320456,"fiber_id":10961280,"process_id":3416,"file":"C","lineno":0,"method":"325"}

The cloud controller logs this:

"GET /staging/buildpack_cache/b687443f-f6a2-4021-84ad-13e9e8b54c86/download HTTP/1.0" 400 106 0.0179

Anyone seen this?
I'm running against BOSH-deployed CF v2.
This has been working, but I switched focus for a few weeks and now I can't deploy.