That's right!  You tell those strings who's boss!  And while you're at it, set the example by replacing your bow as a warning:  "this is what happens when you break on me, you get replaced!"

@ StoneDog: If the A string that broke was the "Zyex" A string, D'Addario had a bad batch of "Zyex" string's several month's ago. The problem has since been corrected. The two set's of "Zyex" string's I bought had both A string's unravel, both in the peg box and one of the two also started with a nick between the bridge and tailpiece.

This has been confirmed with, Mike at Fiddlershop.

A couple week's ago I called the Fiddlershop to inquire if there had been any other problem's with the A string's unraveling, Mike said he hadn't heard of any other complaint's or problem's and while I was talking with, Pierre, Mike called D'Addario and they said they had had a problem with only the Zyex and the problem had been remedied.

This thread remind's me, I have to call, Mike again, he said, D'Addario was sending him some replacement string's and to call him the following week and he would send two new A string's to replace the defective one's and I totally forgot to call.

Ken.