Hi Fran,
First, please pester me as often as you want, only problem is may be you’ll reach my limitations too soon. I did pester specially Gonçalo, but also Marc and Leon when started using VRay… well, they insisted I should use it, so… 
Select all your glass objects and exclude them from GI genreate and recive, in VRay, System Object settings.
What some people did was calculate and save imaps with glass window objects hiden and then reuse GI from precalculated file, and turn glass on at render time for reflection/refraction…
We can say it won’t contribute to the illumination,
For illumination test renders:
-Inmediatly low GI Irradance map Min/Max rates to -5,-4 (for instance)
-HSph subdivs, from 100 to 50 this will cut Imap calcualtion time about the half (I’d have said start with something as low as 20, that will have impact on Imap quality, but much much greater on render times, so until you have Illumination roughly set, keep it low, you’ll be able to crank it up later)
Photometric lights in your scene… what’s the purpose? to reproduce accurate actual projected fixtures behaviour? is that really necessary?, if it is then I probbly won’t be of much help, but if it is not, if you only need to produce the “feel”, first whing we do is delete them.
A similar level of general illumination can be achieved without the lights, increasing GI and Environment multipliers.
Try this: delete all your Photometrics (or turn them off) , set First diffuse bounce multiplier to 3,0 Secondary Bounces to 1,0 (it’s max value in 1.09) GI Environment muyltiplier to 7,0.
Well, now the scene is not what you want yet, but if you turn antialiasing adaptative to -2, 1 it renders in some 51 seconds (800x600) dual xeon 2,8 downgraded to 2K SP4 because of XP problems, this mean NO HT enabled.
From here we coult try to reintroduce the artificila lights if they are needed, my apporach would be fake them of course, not using actual photometric lights (unless that was actually the reason of the visualization)
Geometry with selfilluminated material and VRayMtlWrapper has worked great for me, standard lights with limited ranges (a la fakiosity) have also worked great in some other situations… as we add further lighting, we can then turn the blowed up multipliers for environement down, and adjust First diffuse bounce…
Later, we might consider lgith portals or simply area lights for the window openings (so we fake the glass we removed from GI partial light scatering)
I know, still a long way to go, and I am not best consultant for interior images + I am a faker, but I think really fast test render times are a must, specially when we have lot of testing ahead.
hope it helsp somewhat, later more.
I’ll emailyou the scene I’ve downgraded as described above, just open it, and hit render, and see if it helps or not.
Cheers
Fermí