AdamK, did the software NOT lag over time for you, and then you upgraded to a newer version and it started lagging? That would surprise me.
It started to lag after I updated to new hardware, a Lenovo X200. The version of TD I was using did NOT change. I always updated TD 2.5.x when new versions become available, so it was the latest version which I had been running on my Lenovo X61s. The X61s was running Windows 7 32-bit and the TD ran perfectly.
My current hardware is relatively new (a couple of months old), so the Windows 7 64-bit installation is "fresh". The only thing I did was install all of the Windows Updates and my typical program set. All other programs are running as expected. I noticed the slow down the first time a ran a tournament for my poker group. I figured I just hadn't rebooted for a while?? I've been running TD for this group for a number of years, about once a month. This is a relatively fast computer with 4Gb of RAM. It's never been infected, nor has it ever exhibited any other "strange" behavior. I'm an IT director and do some programming so I <think> I'm a pretty good judge of whether a machine is in good operational condition. I carry this laptop between work and home and it is my primary computer. It runs GREAT!
<Something> is definitely up even with the latest BETA version. The slow down still exists, but as we've discussed, it's "better". Hopefully this issue will remain an isolated problem for a small percentage of your users. Happy hunting!