check http://codingangel.com/category/c/ if you click next page or older entries link, ie, (http://codingangel.com/category/c/page/2/) ,but it redirects to old link http://codingangel.com/category/c/, i am using Atahualpa theme, please help me to solve the problem.

It works fine for me.

how long has this issue existed?
if it just started, what did you change?
have you tried temporally disabling ALL plugins at the same time
have you made any recent changes? updates?
have you tried clearing your browser cache?

also, don't double post. I have deleted the post in the other thread.

Yes, all plugin i have disabled, but the problem is not solved, home page is good and working its older pages. but the issue in category page...what do to..urgent

If it is urgent, then I'd suggest answering all the questions I've asked

issue solved....but i have another problem../page/2 and so on has no description, i using all in one seo, but its not working, and also archive page eg. 2012/1 etc... many duplicate description has occurring, please tell me how to solve it...

If the plugin isn't working, I suggest you contact the plugin author or use another plugin.