J2SE Version (please include all output from java -version flag):
  java version "1.6.0-beta"
  Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-beta-b59)
  Java HotSpot(TM) Client VM (build 1.6.0-beta-b59, mixed mode, sharing)

Does this problem occur on J2SE 1.4.x or 5.0.x ? Yes / No (pick one)
  Not sure - if pressed I could try and reproduce on an earlier version.

Operating System Configuration Information (be specific):
  Windows XP SP2

Hardware Configuration Information (be specific):
  1GB memory:
  processor: Intel Pentium 4 2.54GHz (not hyper-threaded)

Bug Description:
  Everything has been running fine in my test environment. Yesterday I
  installed a Linksys WA354G router and now I keep getting an application
  lockup with 100% CPU utilisation. Our Azureus users have occassionally
  reported such problems (100% CPU use that is) and we've never been able
  to track it down. Recently (with JDK 1.5 help I added a monitor thread
  that measures thread CPU times to spot which thread is looping to cause the 100%
  problem. This has revealed the thread to be:

[7:34:56] Thread state: elapsed = 10000, cpu = 14751, max = Keep-Alive-SocketCleaner (14735/147%)
[7:34:56] java.io.BufferedInputStream.fill(Unknown Source),
java.io.BufferedInputStream.skip(Unknown Source),
sun.net.www.MeteredStream.skip(Unknown Source),
sun.net.www.http.KeepAliveStreamCleaner.run(Unknown Source),
java.lang.Thread.run(Unknown Source)
[7:35:06] Thread state: elapsed = 10000, cpu = 9936, max =
Keep-Alive-SocketCleaner (9921/99%)
[7:35:12] java.io.BufferedInputStream.fill(Unknown Source),
java.io.BufferedInputStream.skip(Unknown Source),
sun.net.www.MeteredStream.skip(Unknown Source),
sun.net.www.http.KeepAliveStreamCleaner.run(Unknown Source),
java.lang.Thread.run(Unknown Source)

Looking at the code it appears you are trying to skip a number of bytes:

while (n < remainingToRead) {
    remainingToRead = remainingToRead - n;
    n = kas.skip(remainingToRead);
}

and that for whatever reason the "skip" method is returning less than
expected. As this has only happened since I installed the new router, and we
use http to configure the UPnP aspects of the router, I guess this is
something specific to do with the linksys router's behaviour regarding
keep-alive stuff.