Just got this crash after using a mining laser, and cant not rejoin my server. Only way i was able to get back on it was to delete the world.
http://pastebin.com/u11wcuCa
Edit: After looking thought the error log for the launcher I see the following. Full log here. http://pastebin.com/0sQpXuzJ
21:39:02 [INFO] net.ftb.gui.LauncherConsole$OutputOverride.write:65 From Console: 2012-11-10 15:39:02 [WARNING] [ForgeModLoader] Could not load forestry config, due to java reflection failing!
beeBreedingMode
21:39:03 [INFO] net.ftb.gui.LauncherConsole$OutputOverride.write:65 From Console: 2012-11-10 15:39:03 [INFO] [STDOUT] CONFLICT @ 357 item slot already occupied by ic2.common.ItemBlockRare@528571 while adding ic2.common.ItemBlockRare@1b6c0f5
21:39:03 [INFO] net.ftb.gui.LauncherConsole$OutputOverride.write:65 From Console: 2012-11-10 15:39:03 [INFO] [STDOUT] CONFLICT @ 366 item slot already occupied by ic2.common.ItemBlockRare@1361eef while adding ic2.common.ItemBlockRare@28ff62
http://pastebin.com/u11wcuCa
Edit: After looking thought the error log for the launcher I see the following. Full log here. http://pastebin.com/0sQpXuzJ
21:39:02 [INFO] net.ftb.gui.LauncherConsole$OutputOverride.write:65 From Console: 2012-11-10 15:39:02 [WARNING] [ForgeModLoader] Could not load forestry config, due to java reflection failing!
beeBreedingMode
21:39:03 [INFO] net.ftb.gui.LauncherConsole$OutputOverride.write:65 From Console: 2012-11-10 15:39:03 [INFO] [STDOUT] CONFLICT @ 357 item slot already occupied by ic2.common.ItemBlockRare@528571 while adding ic2.common.ItemBlockRare@1b6c0f5
21:39:03 [INFO] net.ftb.gui.LauncherConsole$OutputOverride.write:65 From Console: 2012-11-10 15:39:03 [INFO] [STDOUT] CONFLICT @ 366 item slot already occupied by ic2.common.ItemBlockRare@1361eef while adding ic2.common.ItemBlockRare@28ff62