So it looks like when you download SK instead of playing in the browser, it comes packaged with a copy of the JVM -- 1.6 update 7, which is at least a few years old!
The shortcut it drops on the desktop points to this copy of the JVM instead of the one installed on my system proper, which seems lame considering it's not the ideal JVM for my (64-bit) OS.
If I rig up the shortcut to point to my actual installed Java version (1.6 u24 x64), the SK downloader opens and gives me an unhelpful message "Multiple instances of this application's installer are running. This one will stop and let another complete."
If I want to play SK with the ideal 1.6u24 x64, it looks like I MUST play in a browser!
wat do?
I changed the desktop shortcut's path as you describe after installing the 64-bit JRE, and I haven't had a single problem. Dunno what's wrong on your end.