Error trying to mine with stratum_proxy I'm giving a specific case here, but I think I have seen the same error trying to use stratum_proxy for any pool and coin I have tried.

When wemineltc.com briefly had a getwork server up, cudaminer worked great! But now that they're back to stratum only, I'm trying to get that to work.

I run the stratum proxy that I get from wemineltc and see this:

C:\dev\cudaminer-2013-04-14\stratum_proxy.exe\twisted\web\util.py:372: Deprecati
onWarning: Passing filenames or file objects to XMLFile is deprecated since Twis
ted 12.1.  Pass a FilePath instead.
2013-04-16 08:24:07,302 WARNING proxy jobs.&lt;module&gt; # C extension for midstate n
ot available. Using default implementation instead.
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Stratum proxy version: 1.
3.0
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Trying to connect to Stra
tum pool at eu.wemineltc.com:3333
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Setting PoW algo: scrypt
2013-04-16 08:24:07,621 INFO stats stats.print_stats # 1 peers connected, state
changed 1 times
2013-04-16 08:24:07,621 INFO proxy mining_proxy.on_connect # Connected to Stratu
m pool at eu.wemineltc.com:3333
2013-04-16 08:24:07,621 INFO proxy mining_proxy.on_connect # Subscribing for min
ing jobs
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # -------------------------
----------------------------------------------
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # PROXY IS LISTENING ON ALL
 IPs ON PORT 3333 (stratum) AND 8332 (getwork)
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # -------------------------
----------------------------------------------
2013-04-16 08:24:07,838 INFO proxy client_service.handle_event # Setting new dif
ficulty: 128
2013-04-16 08:24:07,839 INFO proxy client_service.handle_event # New job c9 for
prevhash d2c7e1c2, clean_jobs=True


Then I run cudaminer with the following batch file (on windows 7 64 bit):

cudaminer.exe -o 127.0.0.1:8332 -O user:password


And see this:

C:\dev\cudaminer-2013-04-14&gt;cudaminer.exe -o http://127.0.0.1:8332 -O user:
password
           *** CudaMiner for nVidia GPUs by Christian Buchner ***
                     This is version 2013-04-14 (alpha)
        based on pooler-cpuminer 2.2.3 (c) 2010 Jeff Garzik, 2012 pooler
               Cuda additions Copyright 2013 Christian Buchner
           My donation address: LKS1WDKGED647msBQfLBHV3Ls8sveGncnm

[2013-04-16 08:29:52] 1 miner threads started, using 'scrypt' algorithm.
[2013-04-16 08:29:52] HTTP request failed: The requested URL returned error: 401

[2013-04-16 08:29:52] json_rpc_call failed, retry after 15 seconds


I have tried a few different things but I always get that 401 error. Any ideas on resolving this?
The problem was with windows firewall. Turned it off, tried again, it worked. Turned it back on and set the appropriate windows firewall exceptions for stratum_proxy and cudaminer and it worked.

I had this problem suddenly appear again this morning. Turning off firewall made no difference. I changed cudaminer to point to my machine ip address instead of 127.0.0.1 and then it started working.