Freezing after 2-5s Streaming from SlingBox

I am having an issue setting up my Raspberry Pi as a Slingbox client. I am using the native Slingplayer capability in XBMC. I have also purchased and installed the license for VC-1 and MPEG-2.

The video starts out garbled and pixelated with the wrong colors (everything looks white and ghostlike), then after 3-5 seconds, the video freezes and the top right corner says "Buffering." After that finishes, the video is still frozen. The RPi is still responsive, but no video streams.

This is not an ISP issue because I can stream fine on a computer. I also verified that I can play other videos such as from YouTube with no issue.

All I can think of is to attach the relevant lines from xbmc.log:

2:13:25 T:3035541504 NOTICE: COMXPlayer: Opening: sling://administrator:passwrod@domain.org/
12:13:25 T:2755855376 NOTICE: COMXPlayer::OnExit()
12:13:25 T:2755855376 NOTICE: OMXPlayer: closing audio stream
12:13:25 T:2755855376 NOTICE: Closing audio stream
12:13:25 T:2925523984 NOTICE: thread end: OMXPlayerAudio::OnExit()
12:13:25 T:2755855376 NOTICE: OMXClock using video as reference
12:13:25 T:2755855376 NOTICE: OMXPlayer: closing video stream
12:13:25 T:2755855376 NOTICE: Closing video stream
12:13:25 T:2695693328 WARNING: CRenderManager::FlipPage - timeout waiting for flip to complete
12:13:25 T:2695693328 NOTICE: thread end: video_thread
12:13:25 T:2755855376 NOTICE: OMXClock using video as reference
12:13:25 T:2755855376 NOTICE: COMXPlayer::OnExit() deleting demuxer
12:13:25 T:2755855376 NOTICE: COMXPlayer::OnExit() deleting input stream
12:13:26 T:2755855376 ERROR: Close - Error disconnecting from Slingbox: domain.org
12:13:26 T:2755855376 NOTICE: Thread COMXPlayer start, auto delete: false
12:13:26 T:2755855376 NOTICE: Creating InputStream
12:13:27 T:2755855376 NOTICE: No SlingboxSettings.xml file (special://masterprofile/SlingboxSettings.xml) found - using default settings
12:13:30 T:2755855376 NOTICE: Creating Demuxer
12:13:33 T:2755855376 NOTICE: Opening video stream: 0 source: 256
12:13:33 T:2755855376 NOTICE: OMXClock using video as reference
12:13:33 T:2755855376 NOTICE: Creating video thread
12:13:33 T:2695693328 NOTICE: Thread COMXPlayerVideo start, auto delete: false
12:13:33 T:2755855376 NOTICE: Opening audio stream: 1 source: 256
12:13:33 T:2755855376 NOTICE: Creating audio thread
12:13:33 T:2925523984 NOTICE: Thread COMXPlayerAudio start, auto delete: false
12:13:33 T:2695693328 ERROR: Output - renderer not started
12:13:33 T:2695693328 ERROR: Previous line repeats 15 times.
12:13:33 T:2695693328 WARNING: CRenderManager::Configure - timeout waiting for previous frame
12:13:33 T:2695693328 NOTICE: Display resolution DESKTOP : 1920x1080 @ 60.00 - Full Screen (16)
12:13:34 T:3035541504 NOTICE: Using GL_TEXTURE_2D
12:13:34 T:3035541504 NOTICE: GL: Using BYPASS render method
12:13:34 T:3035541504 NOTICE: GL: NPOT texture support detected
12:13:37 T:2925523984 NOTICE: OMXClock using audio as reference

Has anyone seen this or give advice on things I can try to solve or debug this?