Will having different links to the same page adversely affect SEO placement?

I am revamping a website with an OK Google ranking to try and improve page rank. I run the site with PHP with SE friendly links (no query strings). The base-names of the URLs were "index.html", but I can call them anything, and I need to know if I have some of the pages marked as "index.html" and other named "video_dvd.html" that bring up the same page will be considered SE spam. Example:

www.site.com/catalog/122/index.html
www.site.com/catalog/122/video_dvd.html
www.site.com/catalog/122/video_dvd_featuring_widgets.html

All three of these links would go to the same page, as the PHP only reads the ‘catalog’ and ’122′ part of the URL to lookup the information from the DB. I’ve kept things uniform by having the same types of links on one page (for example, the index page has index.html links, and the product directory has the ‘video_dvd.html’ links.

Is this type of SEO kosher for Google and the like, or should I keep one uniform link for each page?

this will cause duplicate content. and Google will only give value to one of them…

my suggesstion..
if your page/catalog/122/index.html is talking about action DVD.

use /catalog/122/action-dvd-dvdname.html

also, make you redirect the old page to new page…(301 redirect only)