I just accidentally notice that there might be a memory leak in the Windows client.
The way I found this is by my laptop telling me that he had hit the page size limit (of over 1 GB) I had some other applications running, but I started task manager and noticed that the memory usage of the client was steadily climbing (even though I was just standing there facing a wall). Between starting to observe it rose from around 260 MB to 295 MB. Quitting the client took very long and opened up pretty much the 300MB of page file space.
My client was lagging today, but I thought it was the number of users. But I think it probably was this issue. I have a high end machine runnign 512MB mem and usually get around 60FPS almost everywhere execept main square.
Hope this helps,
- F