Getting "page not found" on profiles.

Hi all - I keep having to work on other projects and when I get back here it is like I am starting all over.  I have an old site I upgraded to 7.1 - but had to work on a paying project so never really completed it.   I am just getting back to it, and I noticed the profiles aren't even showing since the "upgrade".   The site is at http://caltrade.com/community - click any profile link, for example http://www.caltrade.com/community/wangel  - the profile has been approved, and seems to be there, but is now a broken link.   Probably this is just some simple setting - at least that is what I hope it is.  No critiques please - I know it is a mess.  I have a 7.09 site that isn't too bad, but I just haven't had time to get back to this.   

I suspected you did not check any of the module. So i checked for you. http://www.caltrade.com/community/m/events/home/

Same thing as the profile.

There is only one explanation for that.  Missing .htaccess file or mod_rewrite not enabled. What ever the cause, it boils down to one thing. The url rewrites are not working.

Proof. Profile accessed without the friendly url. http://www.caltrade.com/community/profile.php?ID=10

Thanks Deano, that was it.  I found an almost empty .htaccess file in there,and another labeled .htaccess-old  - though for the life of me I don't remember doing that.  I changed it back and it works now.  Thanks for your help.