I'm on OSX 10.8.5, and I have had a few instances where Oracle SQL Developer gets "stuck" scrolling in the a worksheet or the connections/object pane. I'll be trying to scroll in one direction, and SQL Developer will snap the scrolling all the way in the other direction repeatedly/constantly. A full app restart seems to resolve the issue. Never saw this on the 3.x series, but it appears to impact both EA1 and EA2. The first time I saw it on the worksheet, I was dragging a table with lots of columns into the worksheet to produce a select statement. The select statement scrolled off the available space, so this may be what triggered it in this instance, although I have no way to verify.