The conti seal in the tire is pretty much nothing more than that fix a flat stuff you can get at places.. It's about 8 lbs of this stuff coated on the inside of the tire. It's meant to seal small punctures such as a nail in the tire. It of course isn't full proof if there's not enough of the substance around the puncture area or the puncture is too large then it may not be able to seal it properly. I'm sure I had a nail or two during my experience with them and I didn't have a problem the entire year I ran them. If you have a warranty try to get it replaced if you don't then consider purchasing a new tire. If you don't want to pay for the tires then i'd suggest taking a look into a new brand of tire.
Right now i'm running the hankook ventus v12's and i'm loving them.