The first time I used Power Pro 30lb. test on a Shimano Chronarch 100SF. I backed the line with monifilment 10lb. test,the line broke after several casts at the spool.I tried again the same thing happened,I thought this to be very rare,I also checked all the guides on my rod they were fine. Can any one offer any suggestions,this has never happened with any of the other types of line I have used.