My FTB Direwolf20 server is leaking!
2013-04-11 22:29:24 [SEVERE] [ForgeModLoader] Detected leaking worlds in memory. There are 4 worlds that appear to be persisting. A mod is likely caching the world incorrectly
2013-04-11 22:29:24 [SEVERE] [ForgeModLoader] The world 6e929b52 (world) has leaked.
2013-04-11 22:29:24 [SEVERE] [ForgeModLoader] The world 28db4ccf (world) has leaked.
2013-04-11 22:29:34 [WARNING] [Minecraft] Can't keep up! Did the system time change, or is the server overloaded?
This is on a server I've just started up. What can I do?