This is with NGUI 3.5.1.
I have a UIScrollView with a grid in it that gets populated at runtime. After updating to 3.5.1, the scrollview doesn't scroll unless dragged with the mouse... but only when connected to a scroll bar. The scroll bar foreground winds up scrunched up at the top of the scrollbar (the size is set to 0), and dragging it doesn't work correctly. Using the mouse wheel over the scroll view doesn't work either. *However*, dragging the panel itself via UIDragScrollView causes the whole thing to kick into gear and start working.
Removing the scroll bar, or just disconnecting it so that the scroll view doesn't have a link to it makes the scroll view work just fine. I tried replacing the scroll bar with a fresh copy of Control - Simple Vertical Scroll Bar, but that didn't make a difference.
I tried searching the forums, but I haven't found anything similar to what I'm running into, so I have to assume that I'm setting something up wrong, or something changed so that the way it was set up previously is no longer valid. For reference, the panel is not static. I saw some references to script order of execution. Could that be what's causing this?