Always getting error 404 on reverse proxy requests (ARR_DISK_CACHE_GET_FAILED)

Guys,

For some bizarre reason my application is not properly rewriting through AAR.  I always get a 404/501 error with a strange "ARR_DISK_CACHE_GET_FAILED" error.  An important thing: It only happens on this particular application. Same route work on other test app.

Most bizarre thing: If I access same rule (/test poiting to external URL) on a different application, then it will work on the first application until cache expires. When it expires, it will return 404/501 again.

Trace Log: http://pastebin.com/2439JH51

My setup: IIS 7.5, Win Server 2008, ARR 2.5, .NET 4

Ideas?

thanks.