Cannot obtain block errors

I've been seeing a lot of errors from dfs for the last couple days. The exception that I see is:

java.io.IOException: Could not obtain block: blk_2867431916903738534 file=/user/oom/big-rand/part000271 offset=0 at org.apache.hadoop.dfs.DFSClient$DFSInputStream.blockSeekTo(DFSClient.java:532) at org.apache.hadoop.dfs.DFSClient$DFSInputStream.read(DFSClient.java:641) at org.apache.hadoop.fs.FSDataInputStream$Checker.read(FSDataInputStream.java:83) at org.apache.hadoop.fs.FSDataInputStream$PositionCache.read(FSDataInputStream.java:158) at java.io.BufferedInputStream.fill(BufferedInputStream.java:218) at java.io.BufferedInputStream.read1(BufferedInputStream.java:256) at java.io.BufferedInputStream.read(BufferedInputStream.java:313) at java.io.DataInputStream.readFully(DataInputStream.java:176) at java.io.DataInputStream.readFully(DataInputStream.java:152) at org.apache.hadoop.io.SequenceFile$Reader.init(SequenceFile.java:264) at org.apache.hadoop.io.SequenceFile$Reader.(SequenceFile.java:248) at org.apache.hadoop.io.SequenceFile$Reader.(SequenceFile.java:238) at org.apache.hadoop.mapred.SequenceFileRecordReader.(SequenceFileRecordReader.java:36) at org.apache.hadoop.mapred.SequenceFileInputFormat.getRecordReader(SequenceFileInputFormat.java:53) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:105) at org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:866)

I haven't had my fingers in that code recently, does it ring any bells for anyone?