I'm experiencing hangs as well; the usually occur when trying to select a line. The hangs take about 10 seconds. They occur only when "Hardware acceleration" is ticked in Preferences. Installing the ThawUp patch did not help.

Sketchup version: 7.0.10248

Video chipset: GMA X3100

Model Name: MacBook
Model Identifier: MacBook4,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.1 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 3 MB
Memory: 4 GB
Bus Speed: 800 MHz
Boot ROM Version: MB41.00C1.B00
SMC Version (system): 1.31f0