Sazzy, he may have put your new email together with the MS, thinking he'll let you know when he's looked properly at the whole thing - (in an ideal world he should at least have acknowledged it of course, but it's not an ideal world). They're busy with the London Book Fair at the moment, too, which may not help.
It's hard to know what to do, but if it were me, I'd leave it another couple of weeks - i.e. till after the fair - and email saying you just wanted to check if he got the previous one, as you'd be happy to send him the revisions. As Kat says, that ought to jog his memory. Some are just much more disorganised and/or busy than others. (I've had keen phonecalls months after I sent my sample, and guilty phonecalls from assistants - 'we've just found it buried in a pile in his office'
. I wouldn't have thought, though, that a revised or otherwise opening will be the make-or-break factor at this stage. If he loves it except for the opening he'll ask to see the new one, and if he doesn't quite, then the changed opening won't convince him anyway.
Kat, how annoying! But it sounds as if it got proper consideration, anyway - I doubt if your call tipped the balance. Unless you're nursing secret doubts about some aspect of it that you should listen to and get revision, I'm sure the advice to get it out there again is the right one. It's the best cure for that oh, poo feeling.
Emma
<Added>Tut! 'get
revising'