1.4.6 server drop in performance

Server performance dropped drastically when upgrading from 1.4.5 to 1.4.6. The server is running the same mods(updated to 1.4.6 of course). The server is running with 1-2 people at most(it's a private server). In 1.4.6 the server is constantly running at lvl0 tick ~50ms and the log has "can't keep up" far too often in it. Another issue that has appeared is "flickering" blocks and laggy behavior(it's a lan server so the connection isn't the problem). In 1.4.5 the server would run at around lv0 tick 5-25ms(at most!).