Recently I’ve observed that menus from grass are shown on top on other windows. This also happens with other applications running on X. So maybe this is off topic, but just in case somebody has noticed the same.
Model Name: iMac
Model Identifier: iMac5,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 2 GB
Bus Speed: 667 MHz
Boot ROM Version: IM51.0090.B09
SMC Version: 1.8f2