Help with URL structure

[blackystrat]

Hello Friends,

I have been working on promoting ecommerce stores for quite a while now. However of late I am experiencing a strange issue with one of my clients.

The website has URLs like http://www.example.c...-name-c-10.html and http://www.example.c...me-c-10_11.html and so on.

So far so good - but whenever there are some modifications on the website in the form of adding/ removing products, the URL of the pages suddenly changes

Such as from http://www.example.c...-name-c-10.html it becomes http://www.example.c...me-c-10_15.html

and from http://www.example.c...me-c-10_11.html it gets http://www.example.c...c-10_11_12.html

This is getting really frustrating since we have no idea why the URLs are changing like this and how to prevent this from happening in the future. This is affecting the search engine ranks of the website since with a change in the existing URLs, all links pointing to those URLs get wasted.

Any advice on this would be greatly appreciated.


Thanks