Erh, lol, i don think its possible for you to tune up an octave and have the string not snap.
Anyway, my guess is that the guitar hasnt been set up? Cus set up is REALLY important. This includes the bridge height, saddle height, nut height and even fret height.
And possibly because you're not used to it or sth. It IS hard when you're first starting out.
So do get your guitar to a pro who will asses the situation (normally its free). And if need be, set it up (about 50 to 100 bucks). It not only makes playing easier, staying in tune easier it actually makes the guitar sound better. It possibly solves many other problems like easy string breakage or fret buzz and what not. So... Thats my humble opinion.
GOOD LUCK!