The following links will provide you with some information that might help you.
Finally, we recommend you to remove the SlingPlayer software version from your computer and use the following link in order to get the latest SlingPlayer software version.
Same exact story here matrazzo. My 1st year and a half with the SlingPlayer was flawless, on my computers and my phone. Ever since they started offering the web based viewer and gave up on the standard player, the quality has been horrible. It does not even steam enough to play 2 minutes of mediocre video without freezing up on my laptops and my phone and it is not my connection! I have a strong connection on both ends. Very Frustrating.