The mistake was when you allowed white to get two rooks onto row 7, although the first rook was trouble enough. Having two rooks aligned behind your pawn lines spells trouble, and it was definatly a contributing factor to your loss. In situations where there are 2rooks vs 2rooks and no other pieces save pawns, its better to keep a minimum of one rook guarding your back lines, preferably two.
At about turn 24 you had two pawns on the a and b files to their one pawn. I would recomend that you should have advanced these pawns, keeping your rooks behind them. Even if you had exchanged these two pawns for their one, you still had a one pawn advantage.
Moving 24. Rd7 instead of Rd2 would have guarded your back lines and allowed you to slip one rook behind each of the a/b pawns.
Also, in these circumstances where there are few pieces on the board, exchanging pieces of equal value is greatly to your favour, so a rook rook exhchange would help you. This greatly reduces your opponents ability to disrupt you lines, and then you can (carefully) exchange pieces until you get a pawn and king vs king (preferably a central pawn). From there it should be a win to you.
This is my game from a Handicap game at my club!
My opponent was not that strong and I was two pawns up untill I threw the game away terribly as you will see! And just to let you know his grade is not real; just an estimate given by the club which is a compulsory measure for our area's league. I unfortunately lost and I would really like it if people could help me out with basic things I did wrong in the game and all my mistakes etc... and then secondly how I sud of converted that two pawn lead into a win! BTW I was black!