People make up crap all the time, don't ask me why. Maybe it was his way of asking to protect his wallet but didn't want to sound like a noob...in some strange way.
Anyway, Op. HAVE you been in contact with anyone recently? I mean here on the forums or skype etc. Have you downloaded any files recently from untrusted sources?
Viruses are increasing now that Bitcoin is becoming more popular, that's why having a offline computer is better.
That's true, but why would he do two transactions if it were a thief? that doesn't make any sense. Obsiously to gain access to his wallet in the first place he must of been pretty intelligent, unless the OP made a silly mistake. Or, he followed a script. But, even then going undetected, he must of been tech savvy at least, as the majority of Bitcoin users are. I'm not saying that makes you smart. But, it just doesn't make any sense to leave anything behind.
If you were on a island with not having food for days and found a few melons, would you take them all and store them safety to stop animals eating them or would you take a few and leave some?