On the basis of the core rules, there is no clearcut answer on whether you can or cannot Hide while sniping. It is all just personal opinion on what works best.
I rather strongly feel that Hide should work more or less like Invisibility with respect to attacks: Attacking automatically reveals the location of the attacker; you may attempt to Hide again, terrain & circumstances allowing.
My reasoning is that Hide is potentially much more powerful than Invisibility for the simple reason that Invisibility is easily defeated by low level magic, while Hide cannot be countered by magic at all. Look very carefully at the spell True Seeing, for example.
Furthermore, Hide can be easily boosted by relatively cheap, and accessible magic items, feat, abilities.
The net result is that an optimized Rogue can easily automatically get a Hide result in the mid 40's at 10th level -- undefeatable by even an optimized Spotter. At really high levels, you can see Hide rolls up in the 60's.
And I haven't even started talking about Shadowdancers.