As an FYI: I'm working on a data set that I've got 2 joins to external data. I discovered today that if you're styling features based on a joined property, if the "field" has the same name, the styling won't see the join data source as part of the field name - that you can inadvertently style on the wrong data set - it treats the data source as an "or" function.
Just thought I'd share today's lesson learned....
Intel Xeon E5630@2.53Ghz
NVIDA Quadro NVS420 Dual Monitor
12GB Ram / Win7 Professional 64bit SP1