you put them in /bin? and they if you ls -l they are both user root and group root? and they for certain have execute permissions? and finally did you try both sh and bash in the scripts? I had bash but you are probably running busy box so the line should probably read #
!/bin/sh.

can you cd into /bin and run ls -l unlock lock and post the output?
then post the actual contents of the 2 files you created?

There is a simple answer for this ...

btw the command in the files (the line ending in either true or false) can be run manually to lock/unlock the desktop. so you can run the commands to see if the actuall hildon desktop locking/unlocking is working. putting the commands in the files, making them executable and putting them in /bin is just to make it easier to unlock/lock by being able to just type lock or unlock as opposed to having to remember the cryptic command that ends in true of false.