There are lots of problems on CF and it's really hard for me to find problems that are interesting and I can solve them with my programming knowledge! Can you please share the problems that you have seen and they don't really want a high programming knowledge and they are more theoretical? (harder problems are more interesting!)
If I understand correctly your question, you want to solve harder problems that require more theoretical knowledge. Well, I'm not very experienced, but number theory problems are difficult, geometry ones require a big MATH background to solve them (like this one: http://codeforces.net/problemset/problem/696/F) and, if you want problems that require more COMPUTER SCIENCE knowledge, search fancy data structures problems.
http://codeforces.net/problemset/problem/756/D
http://codeforces.net/problemset/problem/547/C
http://codeforces.net/problemset/problem/757/E
There are some of these problems in problemset by Constructive algorithms tag.
Here are some problems I have : 652F - Ants on a Circle 618F - Double Knapsack 341E - Candies Game
a complete theory problem:
643F - Bears and Juice
http://codeforces.net/contest/550/problem/D
Is There anymore suggest ?