Are the requests that you are missing ones that very rarely occur? I know that the requests list is usually the top 100 so if you have a request that rarely happens it might not show up in the list.
David makes a good point. But try filtering the list to look for a specific request as it will filter the entire set rather than just the top 100 at that point. If you have certain transactions that you are always interested in seeing, consider marking them key, also.