Maybe you should look at your setup first, do you have the correct string tension?? do you use a guitar tuner to tune up with? are you tuning in the correct key? have a look at your existing bridge, there is nothing fundemently wrong with your epiphone tunomatic bridge, ive had a Gibson Standard for 10 years and never broke a string, i would buy some fine grit paper, or wet and dry about 800 grit should do it, then sand over the problematic individual saddles, make sure you get in to the ‘V’ grrove too. Also when setting your guitar up try easing off the 2 huge screws on the stop tailpeice, this has an effect of ‘loosening’ the tension on the strings, if all else fails then simply purchase another tunomatic bridge, you can get them from allparts.com and they dont cost very much.