same thing is happening to me
my classic box is in Bogota, Colombia
I watch slingbox from Hamilton, Canada
I'm using win7 in canada
I did noticed that after leaving it "optimizing" for 5-15 minutes, sling box connections in resource monitor starts to "work on it's own" until eventually It starts streaming again, the next time the stream comes on it seems to hold a bit longer than 1 or 2 minutes (which was how long lasts as soon as I start the slingplayer in the beginning), the connections seem a bit different once they normalized in resource monitor. it's like the slingplayer is trying to figure out a way to work around any possible network issues.. but that's my guess because I really didn't do much in the options area. I did also noticed that the ip address where I was connecting at the beginning changed after the stream came back on on its own, I spent a few hours looking at this behaviour and I'm pretty much convinced that is a network issue rather than slingbox problem
one thing I did do though was to disable the buffer since I'm running out of space in my computer.
the problem still persists for me though
I'm going to try connect to the sling box directly with an ip address.
will post if I find any change.