From my experience, it depends on the web page. Snopes, for example, uses a java script that preventes one from selecting text, and that initially fooled me into thinking that aplplied to all pages in Safari 5.1. Not so; I can select text in other pages.
David Kirk at Tech Recipes suggested this override on this particular kind of java script:
"... just past the following into the address bar of your browser and press ENTER:
Worked swell for me.
I know this is an old post however... I need help.
If I could even tell the Amazon "techies" where the problem might lie.... maybe they could help me.
Thanks in advance for any help