IDE issue on Mac 1.6.6

New here - please excuse my noob question as I try to work through the "Getting Started" book examples. I

I have installed the IDE (0022) on a MacBook Pro Running 1.6.6, Java1.6.0_24 ; it talks to my shiny new Uno, downloads the provided examples. However when I try to create my own, or edit some variable, I can't edit the text area. I suspect file permissions so opened everything up for read,write, execute.

If I open and edit the sketch file in an external editor, save, then use the "open" on the IDE, it reads the file fine, runs verify fine, downloads to board and runs. But I still cannot edit the text within the IDE. I can live this way but suspect I have made some simple install mistake.

I still cannot edit even if I choose "new". So I edit (in external editor) the file to follow the book example I'm learning, a minor addition to the sketch. I save the file - update time confirms this.

In the Arduino IDE, which has been running on the side, I select "Open" and point to this (same) file. I appears to read, but the file is the old version, not the update. So I exit Arduino, restart, and select the same file. Now it sees the "new" version, which it can verify and download successfully. I still can't make any edits in the Arduino text area.

Any suggestions appreciated. Is the IDE code open source? If yes where can I get it so I can run in debugger.

-Terry

Is the IDE code open source?

Yes, it is.

If yes where can I get it

Same place you got the executable: http://arduino.cc/en/Main/Software
Below the list of platforms is a link to the source code.