Photoshop :: CS6 Hangs When Using Brush (Mac OS X Lion)

I upgraded to Photoshop CS6 a couple of days ago (jumped the Creative Cloud offer for existing customers) and ever since I've experienced several "hangs" when using the brush tool. In general I can work a few minutes with the brush before I notice that it isn't responding anymore, ie. it doesn't paint or erase or whatever it is I'm using it for. When this happens I can't access the gui anymore and all I have for cursor is the shape of the brush. After that the cursor will turn into that black and white spinning ring of dots and my only way to exit Photoshop is to force quit it.
 
This happens almost every time I use the brush. The OS X Lion installation is brand new, as is the Photoshop installation. No third party plugins installed (haven't had the time yet) and no third party fonts. I use a Wacom Intous 4 with latest drivers.
 
I've recorded a short video of what happens (13MB): URL....This is me working on a texture for a 3D model. I have a couple of layers and when the recording starts I am using a mask to blend two layers.
 
- At around 00:40 the brush stops working so I try to change tool by keyboard shortcut and then by clicking the tool palette.
- At around 01:05 the spinning ring appears and by then I know that I have to force quit.
- At around 01:50 I open up the Activity Monitor (although it can be tricky to read as the Photoshop document refuses to go to the background when the spinning ring appears)
- At around 02:24 the brush starts working again but I still have the spinning ring and I still can't access anything in the menus or palettes.
 
I spend on a single brush session but I'm not sure. What I mean is that if I start brushing away and simply pause once in a while or lift the pen off the board to start a new stroke it feels like the behaviour is less likely to appear. If I however use the brush for a longer period of time without lifting it or pausing, the spinning ring will most definitely appear. It's like Photoshop buffers all my brush movements and then somehow chokes. I could get the spinning beach ball in earlier versions as well but once Photoshop so to say had catched up I could continue working. Now it chokes and I have to force quit.
 
Adobe Photoshop Version: 13.0 (13.0 20120315.r.428 2012/03/15:21:00:00) x64
Operating System: Mac OS 10.7.4
System architecture: Intel CPU Family:6, Model:26, Stepping:5 with MMX, SSE Integer, SSE FP, SSE2, SSE3, SSE4.1, SSE4.2, HyperThreading
Physical processor count: 8
Logical processor count: 16
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