Change your secondary DNS to match your primary. No need for it to point to an external because if you're offline it's moot.
Also, I would suggest using BFGMiner as a proxy instead of slush's. I've seen slush's have issues which couldn't be explained, but BFGMiner is always spot-on.
If possible, use a port other than 8332 to rule out port issues. I usually suggest folks use 8339 or something else easy to remember. Make sure the change is in blade setup, and the proxy knows to listen on the same port.
Yeah,I thought of using BFGminer,however I read somewhere that using it as a proxy requires a x32 OS.
Is it true?
Bfgminer 32bit wont require you downgrade to 32bit os. So that wont be an issue. The main thing that we cant verify is that the IP of the pc running stratum proxy, is the server you have listed in Blade Settings. That will cause your issue, as for the Screenshots of mining proxy, not being able to decode the header, that usually from trying to get mining proxy connected to a getwork pool.
Be sure to double check the Server Addresses in the Blade setting. Need to point to the pc running the proxy