[OS X TeX] TexShop loses all my markup in the .tex file

[Steve]

Newbie problem here.

TeXShop 2.47 on Snow Leopard 10.6.8.

New to LaTeX and also to TexShop. I created a doc, created a PDF, all 
went well. Saved my work, exited TeXShop.

Next time I fired up TexShop, opening the same .tex file gives me a 
blank page and also brings up the earlier PDF. But all my source 
markup is gone.

Also when I double-click on the .tex file in the Finder, it says 
"TeXWorks Mt Lion quit unexpectedly." I double-checked and TexShop 
2.47 is what I should be running on Snow Leopard.

Is there something wrong with my config? How can I sort this out?

Thanks in advance,

Steve L