Tim; Is that a P4 1.7gig? And what motherboard and memory type? And OS, for that matter. I just tried on one of the rain test animations I'm working on, and I do get about a 2 second lag between moving my mouse and the timeline slider catching up. But that is also in a scene that has 211 objects, 1 light, and a poly load of 3,907,796 (And that is a combined Pz3 of Transpond's elvenhome and bridge, and 16 of forester's average rain objects. Not counting the 4 Vue terrains and odd number of plants). That's on an Athlon 1700 with a gig of PC2100 DDR running Win2k.