I have had three of my rackets strung with Pacific Natural Prime Gut 17, mid tension (2 brand new ProKennex 5G and one brand new Redondo). Within two weeks, with no playing at all, all three strings broke by themselves, with no playing whatsoever. They all broke around the grommets. Tension was mid to low (I've got a sore elbow), no humidity, good storing conditions at home (no temperature swings etc). Then I had one of them restrung (at a different store to make sure I do not get the same batch) with Pacific Natural Tough gut 17, and again it broke at a grommet location after two hours of play, no abuse. I guess it must be "Tough gut" as it managed to survive some play at least, while the prime didn't. Did anybody else encounter what looks like a production weakness with Pacific during the last couple months (both stores seem to string a lot of Pacific, so I do not think the string was manufactured a long time ago)?