No, dalle FAQs ufficiali:
If a rogue gets multiple attacks in a round (such as from
a high base attack bonus or the Rapid Shot feat), can she
make sneak attacks for all of them?
Yes, but only if each attack meets a requirement to be a
sneak attack. For instance, a rogue who flanks an enemy can
deliver a sneak attack with every melee attack she makes. A
rogue under the effect of a greater invisibility spell treats every
attack as a sneak attack, since she remains invisible despite
attacking.
If later attacks in a round no longer meet any requirement
to be a sneak attack, they aren’t sneak attacks. For example, a
rogue under the effect of an invisibility spell would deal sneak
attack damage only with her first attack in a round, because she
turns visible as soon as she makes the attack.
Ovviamente durante il primo round tutti gli attacchi del ladro , se vince l'iniziativa, sono furtivi a prescindere che si a invisibile o meno.