I was having the same problem with Maple 12 and Maple 13 on OS X 10.5.8. Manually allowing execute permission for the following files allows me to run xmaple and maple from the command line. I still can't launch the .app and am waiting to hear back from tech support about exactly which files need their permissions modified:

cd /Library/Frameworks/Maple.framework/Versions
sudo ln -s 13 Current    # The installer log showed that this failed.
cd Current/bin
sudo chmod a+x sudo chmod a+x xmaple maple mint maple.system.type linux_shlibs activation TestMaple
sudo chown  xmaple maple mint maple.system.type linux_shlibs activation TestMaple 
cd ../bin.APPLE_UNIVERSAL_OSX/
sudo chmod a+x profile nprofile mserver* mplot* mjava mint help_* mfsd lmutil cmaple 
sudo chown  profile nprofile mserver* mplot* mjava mint help_* mfsd lmutil cmaple 

I have also changed the ownership of the executables to an unprivileged user to prevent them from running as root though I really think this should not be an issue. At least this should let you get up and running with xmaple and command line maple (by running these from the /Library/Frameworks/Maple.framework/Versions/Current/bin/ directory. *Update* The application fails to run because the following file also needs it's permissions set (I found this out based on the tech support suggestion to inspect the Console):

sudo chmod a+x /Applications/Maple\ 13/Maple\ 13.app/Contents/MacOS/Maple\ 13

Now I can also launch the application.