Sun Jan 10, 2010 9:01 pm by lax
It's unlikely that it's a leak in IS, unless it's one that only shows up in LOTRO, and only for certain configurations.
Have you tried disabling SLI? SLI has been shown to do bad things when running multiple instances of a game on the same PC (with or without IS/ISBoxer). I don't know how many people I've disappointed with this news, but when people come to me saying they're using SLI and their game is unstable, disabling SLI usually fixes the problem.
Performance-wise, you're probably going to see better performance by splitting up the video cards and having one render 1 and the other render 2 windows (see "Using multiple video cards" in the Guides section here on isboxer.com). This might not be the best analogy but think of it like if you only wanted to run 1 program at a time on your quad-core PC. SLI is kind of like taking those extra cores, and beefing up that one program instead of lots of programs at a time in parallel. But you're running 3 game instances, not 1, so it is likely better to have them running in parallel rather than beefing up one at a time for each of the 3. But you can worry about that after testing whether disabling SLI helps or not.