[texhax] Does TimeMachine miss most .tex files?

[Murray Thompson]

To support at tug.org

Help please,

On my Mac with OS Snow Leopard,  TimeMachine works nicely but 
I have found FEW of my .tex files are recorded, 
yet my .pdf,  .log, .idx, .aux and all other LaTeX files are recorded.

Is there any reason for TimeMachine to miss the essential .tex files ?
Can I change my use of TimeMachine to catch and hold every.tex file ?
Perhaps TimeMachine records only the files which are on the screen 
when TimeMachine looks for files to back up.

Thanks
Professor Murray Thompson