I am just figuring out gates and how to best use them ... here is some of the stuff I've figured out - it might not be perfect, so someone who *knows*, please correct me if I'm wrong.
I think you probably have to fiddle with the release time and maybe the threshold of the gate .. if the release time is too short (even if the threshold is set right), you may end up with "THWUUu .... and the rest of the uucccckkk - which is the resonance, will vanish below the threshold. If the threshold is set too low, then of course, you'll get all of the bleed. But if you have the threshold set too high, you'll loose much of the attack of the toms, or in some cases, you'll hear the hard hits but won't hear softer hits. Some gates also have attack settings ... so it can get complicated. I typically don't worry as much about attack times ... I use the default in most cases.
So, the bottom line (I think) is that you have to marry the threshold and the release in such a way that the gate opens for the amount of time that the tom will hit. Some gate plug-ins might have presets for toms that can get you maybe half way.
The attack sets the length of time it will take the gate gate to open up fully when the signal is over the threshold, and the release sets how long it will take to close after the signal goes under the threshold (like a fade in, fade out).
Compression can also really help the toms, but depending on the compressor - it can benefit or hurt.
I see you've got the waves diamond bundle - try using the C1 comp/gate or the Rchannel ... unfortunately there aren't any presets for drum kits, but you might be able to find something on the waves forums
