I have the same problem, but solve it.
I place preveously downloaded firmware to Documents and Settings\AllUsers\Application... to flash my device in offline mode.
When I run NSU, it found new version of it and began downloading. Because I'm was sure, than my current version is enough to flash, I click Cancel to stop downloading. My plan was to disconnect from internet and try flashing with current version of NSU and Firmware.
But when I run NSU, it sad "No connection, no flashnig". I forgot, but I thing it was the same mesagge as in title of this theme.
I download separatly new version of NSU, install it, check connection to internet and got the same error message.
I uninstall program, delete all registry and file records that I can find about NSU. Then I restart my computer with Windows XP SP3 English (it is always in up to date state, because I use regulary Windows Update) and install english version of NSU.
And get the same error message.
"Nokia Software Updater has attempted to connect to the internet but has failed three times. This could be because of a poor-quality, slow, or intermittent internet connection, or restrictions due to a firewall
If requested by your firewall, Nokia Software Updater needs the following applications to gain access to the internet:
nsl_host_process.exe
nsu_ui_client.exe":
I read http://www.nokia.ru/support/software/phone-software-update/faq (on Russian) and know about firewall and etc. All Internet connection works fine and in the same configuration of software and OS I flash firmware two weeks before.
Then, I start Microsoft Network Monitor and check, that I got error message with no real connection to Internet from NSU. It was no DNS requests about IP of Nokia Servers.
It was look like caching of error mesage and error state of Nokia Software.
But I was happy, because I had full HDD copy of my system disk. 4 days before I bought new one and previous partition state with system on it was as alternate to shamanizm with NSU.
I install old disk, boot to Windows XP, install over old NSU the same version as in my previous unsuccessfull flash experiments.
When I run updated NSU on my old system, I got normal window messages in now I have new firmware in my phone.
My recomendation for all people is use System Restore before you use NSU. System Restore is not the same as Full system backup, but it is additional possibility to repair buggly Nokia Software.
I think as Microsoft Certified Trainer than it is was not clean Nokia bug. Microsoft don't want to write clean and simple Operating Systems, because all users don't need new and pay more.
And Nokia do the same as Microsoft.
I write this post for all Nokia fun and Nokia engeeners. Nokia, may be YOU have some attention to correct working of your main software, not for new games, pictures and so on.
And If Nokia need test Engeener in India, please, contact me IamDimulyaNo_Spam@gmail.com. I need working visa to stay in India and have some time to help all people get nice phones.
Good luck, brothers and sisters.
