My 5850 is only generating about 220 mhash/s. I've seen many getting around 300/s. Does anyone know what could be causing this? I have no graphically intense processes running, and my drivers are all up to date, so why isn't my card performing like it should?

I'm having some issue... I tried to update my miner, so I deleted my old one, folder and everything included, downloaded the new one, but now when I try to run the application it gives me this:

---------------------------
Errors occurred
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See the logfile 'C:\Users\xxxxxxxxx\Downloads\BTC\guiminer\guiminer.exe.log' for details
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OK   
---------------------------

Then the log file has this to say:

ERROR:root:Exception:
Traceback (most recent call last):
  File "guiminer.py", line 1911, in run
  File "guiminer.py", line 1460, in __init__
  File "guiminer.py", line 1644, in load_config
  File "guiminer.py", line 804, in start_mining
  File "subprocess.pyo", line 621, in __init__
  File "subprocess.pyo", line 830, in _execute_child
WindowsError: [Error 267] The directory name is invalid
Traceback (most recent call last):
  File "guiminer.py", line 1921, in <module>
  File "guiminer.py", line 1911, in run
  File "guiminer.py", line 1460, in __init__
  File "guiminer.py", line 1644, in load_config
  File "guiminer.py", line 804, in start_mining
  File "subprocess.pyo", line 621, in __init__
  File "subprocess.pyo", line 830, in _execute_child
WindowsError: [Error 267] The directory name is invalid