I've been considering it too I'll have to give this a shot tonight. It's consistent with what we know so far. Losing pressure sensitivity in PS is a serious downer; I use a lot of layer tricks and brush settings that aren't available in SBP. Not knowing exactly how the firmware communicates, I wonder if it's getting double requests from two different drivers that's causing the glitch? I've seen some threads on other forums talking about SBP where they had to disable the ISD drivers to get proper pen performance back, but nothing like what we're seeing here. If the glitch does still occur in SBP without the wacom ISD drivers installed then it's probably not a driver conflict, although that certainly could be making the issue worse. SBP glitches a lot less for me than Photoshop. If it's related to how the drivers communicate back to the firmware, I'd imagine that the stock windows pen drivers are a lot less intense. ... You know... as I'm thinking about it, a lot of the time when the glitch triggers for me, it's when I'm opening windows or menus up, or when I close a window and jump back to the drawing canvas in PS. Do you think it's possible that photoshop is actually using both drivers? When moving over menus it would use the basic windows pen drivers, but then when it goes back to the canvas it fires up wintab again? That might explain the doubled data rate we see when the glitch hits... maybe each set of drivers is concurrently filling up a buffer of pen cursor data, and somehow there's a collision, or overlap, where they're both trying to update the pen cursor at the same time? I'm not sure why the glitch would still hit in SBP which doesn't use wintab... I guess I can test it out with wintab completely removed. I could test it in photoshop too, albeit with no pressure sensitivity, but that's fine. I'll use a 20% opacity brush, so when the glitch hits I'll be able to see when it strikes. And I can always run a USBpcap log along with it.