Partial Console Output

2012-06-21 23:00:09 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
java.lang.NullPointerException
        at dl.a(SourceFile:94)
        at rq.a(SourceFile:39)
        at vp.a(SourceFile:171)
        at tk.a(SourceFile:17)
        at mk.b(SourceFile:306)
        at vp.b(SourceFile:53)
        at dl.a(SourceFile:39)
        at rq.b(SourceFile:29)
        at net.minecraft.server.MinecraftServer.o(SourceFile:409)
        at rt.o(SourceFile:208)
        at net.minecraft.server.MinecraftServer.n(SourceFile:361)
        at net.minecraft.server.MinecraftServer.run(SourceFile:308)
        at cp.run(SourceFile:487)
2012-06-21 23:00:51 [INFO] /###REDACTED###:56722 lost connection
2012-06-21 23:01:10 [INFO] ###REDACTED### lost connection: disconnect.quitting
java.lang.NullPointerException
        at dl.a(SourceFile:94)
        at rq.a(SourceFile:39)
        at vp.a(SourceFile:171)
        at tk.a(SourceFile:17)
        at mk.b(SourceFile:306)
        at vp.b(SourceFile:53)
        at dl.a(SourceFile:39)
        at rq.b(SourceFile:29)
        at net.minecraft.server.MinecraftServer.o(SourceFile:409)
        at rt.o(SourceFile:208)
        at net.minecraft.server.MinecraftServer.n(SourceFile:361)
        at net.minecraft.server.MinecraftServer.run(SourceFile:308)
        at cp.run(SourceFile:487)
2012-06-21 23:01:16 [INFO] /###REDACTED###:56272 lost connection
2012-06-21 23:01:16 [INFO] ###REDACTED### lost connection: disconnect.endOfStream
2012-06-21 23:01:23 [INFO] ###REDACTED### logged in with entity id 45390 at (-22842.772341953114, 62.38157553022235, 24324.38392410273)
java.net.SocketException: Connection reset
        at java.net.SocketInputStream.read(SocketInputStream.java:168)
        at java.io.FilterInputStream.read(FilterInputStream.java:116)
        at xq.a(Unknown Source)
        at xq.read(Unknown Source)
        at java.io.FilterInputStream.read(FilterInputStream.java:66)
        at yf.a(SourceFile:167)
        at mk.h(SourceFile:215)
        at mk.c(SourceFile:15)
        at ne.run(SourceFile:92)