I have the SAME HTTP Error issue. At least if there was a darn number associated with the Error message, but there is none. As requested, I provided Roku tech with all the info they need about my app and windows version (see below). They say their engineers are working on it, but it has been a month now, and NOTHING. I am SO disappointed and frustrated. I just want to throw the thing in the garbage and FORGET Roku forever. It works well on my plasma tv, but not on my laptop. I've uninstalled and reinstalled twice now, but it doesn't change a thing.
-OS version and build number from Roku device
-Roku Application Version
-IP address of Roku
-Laptop's software version
-Laptop's brand and model
-IP address of Laptop
-Error message (if it's possible a screenshot)