I'm experiencing this also. Sometimes it takes sublime up to 5 minutes to actually launch. The process list shows it's active, just nothing on the screen...not even a waiting cursor.
I have used Sublime at home for some time and LOVE IT. But then I'm teaching web development and we can't install just anything on the classroom computers. So I had my students download the portable version and save it to their desktop. I think this might be the key here is having the portable version on the desktop (unsure though). It works FINE at home, but on the computers at the school, and the portable version, it's sooo slow we have to double click it and then go do something else to wait for it to open.
If Sublime wasn't so amazing, I'd switch to something else, but I'd really like my students to learn it. Nonetheless, the slowness is really starting to cause issues. Got any ideas or suggestions??? Anyone?
I don't think we can easily take it off the desktop because the profiles are roaming and need to stay connected to the logged in user. So hopefully, if that is the issue, we can find a workaround.