Generally the maximum amount of time is an hour per month of age, that a puppy can be expected to hold itself (except at night when it is sleeping). For a young puppy it is better to have it in an x-pen and with papers it can go on, til it gets a bit older and then people can work on housetraining using the crating method. Otherwise the risk is always that the puppy cannot hold itself, has to go, and keeps going inside the crate. This will make it nearly impossible to properly crate train.
Overall, there are many reasons a puppy could be going in its crate. This could be anxiety at being in the crate, or frustration, or boredom; it could be a urinary tract infection; it could be that he needs more time to be actually crate trained (eg just putting a puppy in a crate doesn't crate 'train', it just crates the dog). Usually you start with just small increments of time, like 5, 10 to 20 minutes, on and off during the day; and you work to make sure the crate has nothing but good associations -- eg you feed inside the crate, leave toys there, toss treats into it, etc. Only after a gradual period of acclimitising will the puppy see the crate as a place to keep clean. If the puppy sees it as a place of punishment or caging, it can be very stressful for the pup to be left inside and this could be one trigger for accidents. If this is the case you need to start over from the very beginning to slowly crate train (as opposed to putting the puppy into the crate). I would first make sure there are no medical reasons for the problem.
Crate training:
http://www.cavaliertalk.com/phpBB2/viewtopic.php?t=2513
Again, just a caution on breeders, as I am not sure how you found yours and if she was someone you could meet and thoroughly check out -- if you did not actually see where the breeder keeps her dogs, and how they are raised, there are breeders who cage them and the puppy will then see the crate as a place to defecate and wee as it will not have had any associations of it as a clean place. There are many very unscrupulous breeders out there, unfortunately. They will have websites that say the right things and a few pics of the dogs in their house and they always say 'raised with the family' -- but the reality is often far different.