I got some user reports about this too.
At my end it looks just like poclbm suddenly stops submitting any shares.

Very sad to hear, poclbm was the best miner ever...

I was even suspecting some http-related library was automatically updated by Windows.
Or some updated antivirus software...

problems on 2 separate Ubuntu 10.04 boxes.          one updated 2 weeks, ago one updated today

-poclbm breaks after stopping and restarting miners.
-Problem occurs on all pools
- miners that were not restarted are working fine so far



one month old poclbm error message

Exception in thread Thread-2:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 552, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 505, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/home/xxxx/poclbm/HttpTransport.py", line 164, in long_poll_thread
    self.queue_work(result['result'])
  File "/home/xxxx/poclbm/Transport.py", line 117, in queue_work
    self.process(work)
  File "/home/xxxx/poclbm/Transport.py", line 76, in process
    self.set_difficulty(work.difficulty)
  File "/home/xxxx/poclbm/Transport.py", line 71, in set_difficulty
    self.true_target = np.array(unpack('IIIIIIII', true_target.decode('hex')), dtype=np.uint32)
error: unpack requires a string argument of length 32



most recent poclbm

Traceback (most recent call last):
  File "/home/xxxx/poclbm/HttpTransport.py", line 51, in loop_internal
    rv = self.send(result)
  File "/home/xxxx/poclbm/Transport.py", line 115, in send
    is_block = belowOrEquals(h[:7], self.true_target[:7])
TypeError: 'NoneType' object is not subscriptable



phoenix miner works correctly (run w/ phatk2)

The failure of GUIminer has forced me to switch to CGminer. That works fine, it's just ugly.

Same mistake with some miners over here. No updates were installed. What else has changed these past few days that could have an effect on guiminer? Some machines I will not be able to check up on for 2 weeks. So, if the problem continues, my hashrate will go down and stay down. Damn. And thank you for your tips considering solo mining. But 7 months is quite a long time sample I would say. Can't say that it was in the beginning only. In fact, I didn't find any blocks for the first 4 months. I will watch closely for the next few months, but my guess is I will have found considerably more blocks than being paid for.

6+ hours.
Are we that unlucky.  It has been a bad day with several 3+ hour blocks.

After the DDoS attack there was a 16 hour round. I've seen some other long ones during normal unlucky days.

It Seems to be going along fine now

Man, it sure is nice to see that percentage going back up again...

Im pretty sure it's a 24 hour time period, that updates after every new btc block is found...