NOTE: this page remains for historical information only. The most recently version of MacOSX supported as of 9.3.1 is 10.7, but not all features are supported on OS versions prior to 10.9.
OSX version 10.6.x brings some new challenges. XTension does run on this version but some people are having some issues that I'll outline below. One thing you will almost certain have to do is to re-install the USB device support. You can do this from the file menu of XTension.
There is one glaring bug in the OS itself. Every 65k apple events one will time out. This isn't a lot, and most people I know that have upgraded haven't really noticed any problem. But XTension sends a lot of events to itself and it's scripts and every 65k event will have an autogenerated reply ID that is out of sync so the reply will never get there. I do not know if this is fixed in any of the 10.6.x udpates or not, if anybody has any information about this please let me know. For this reason, if there are no other compelling reasons to update a 10.5 system for you then there certainly isn't any real advantage for XTension. If you have already upgraded or are getting a new machine it shouldn't cause you too much concern. Whenever possible though you should be wrapping your scripts with timeout values and/or on error clauses to catch and keep going from the timeout rather than just hang.
Not specific to 10.6 but anytime you are bringing an XTension database from one user to another user account, on the same machine or on a different machine you may end up with no write permissions for the database. Repairing permissions in the Disk Utility will not fix this as that only looks at things that were installed with the installer. Since the database is created when you run the program the first time, it's created with that users default permissions, which generally means it's not readable or writable by any other user. So if you just copy it to another users home folder it still isn't readable or writable by them. It's easy to fix though. In the Finder do a “get info” on the database and in the permissions section of the dialog change the owner to the new owner and click on the button to update enclosed items so that the same permissions can be applied to all the contents of the database.
XTension itself remains a 32 bit app for the moment. It has no trouble running on a 64 bit capable system though. It also has no trouble running with a 64 bit kernel. The USB device drivers however are not yet 64 bit. If you are using any of the USB interfaces, the CM15 or CM19 or powerlink then you will need to run your kernel in 32 bit mode or they wont load. Except on some pro and xserve models this is the default condition still but if you forced it into 64 bit mode you will need to set it back. You can find out what mode your kernel is in by reading the system profiler.
Lastly some folks get an error message that the USB drivers were installed improperly and cannot be used. This is likely to be a permissions problem too. The kernel is picky about the permissions on the extensions it will load into itself because of the possibility of abuse at some point in the future. It seems that many hardware devices can suffer from this problem not just ours. There are many discussions of it on the internet, but the solution appears to be resetting the permissions on them manually from the terminal. These instructions seem the most often posted:
cd /System/Library/Extensions sudo find nameofkext.kext -type d -exec /bin/chmod 0755 {} \; sudo find nameofkext.kext -type f -exec /bin/chmod 0644 {} \;
Make sure there is a space between the {} and the \; or it will just error instead of running. The “nameofkext.kext” would be the name of the driver that is causing the problem as displayed in the error message you got. It's not necessary to do it for all of them.