oh dear, my epi LP with the standard bridge and saddle was doing so well, until i changed the thin e string. i put on a deam markley one, because when i ask for spares at the shop thats what they give me. and since then, it has broken heaps of them. the ball on the end keeps popping offf, the string snaps right where it starts to twist around itself on the ball end. wtf? im very fussy with how i string them, i always wrap it around the peg heaps of times (maybe too many?) and there are no sharp bits anywhere. what could be happening?
if they give you the same strings everytime, maybe that brand of strings just sucks nuts.
Maybe a bow in your neck, but I'd run a little file through whatever the string touches just to make sure it isn't a little sharp part.
well the number of wraps doesnt matter in this case (however should only be 2 or 3, for optimal tuning and stability and protection from slippage/bindage), and its not breaking at the bridge so i dont suspect any saddle burs (might want to file and graphite coat your bridge saddles anyway, not to fix this, but just as general good setup tip) so all i can think of is perhaps too sharp of a break angle between the bridge and the tailpiece, resolved by raising the tail piece a bit so the angle isnt so harsh. but a more probable cause is simply bad strings. not saying anything against dean markeley, but maybe the spares are b stock or something. never had this issue.
Try restringing the entire guitar with your brand, see if the problem persists. If it doesn't, they're giving you crappy replacement E's.