Lego Mindstorms NXT 2.1 for Mac does not like Mac OS 10.6.
Google yields a hackaround fix at
Brain Log but I found it only partially correct. It seems the NXT 2.1 software disk is somewhat different from this blog’s listing.
1- Copy all of the files from the install CD to a folder on your desktop. You will be modifying an installer package to disable a piece of it.
2- Find the Parts folder, then open it and find either MindstormsUnivEdu.pkg or MindstormsUnivRet.pkg. (Mine is the latter, I assume that’s the “retail” version vs. the “educational” version.) Right-click and select “Show Package Contents.”
3- Open Contents, then Resources. Right-click the preflight file and select “Move to Trash.” I found this step irrelevant and unnecessary. There is no “preflight” file. Ignore and move to step 4.
4- Navigate back to the MindstormsUniv….pkg bundle and double-click it to start the installer. Follow the instructions to complete the installation.
5- Back in the Parts folder, double-click legodriver.pkg and follow the instructions. This is an installer of its own.
6- You can now go to /Applications/LEGO MINDSTORMS NXT and double-click MINDSTORMS NXT (.app) to open the application.