[toshiba1]

OK I just used TinyUmbrella to backup my shsh blobs on my Apple TV 2. Running Windows 7 64-bit. ATV2 has firmware 4.1.1 (IOS 4.2.1). Allready untethered jailbroken on Greenpois0n rc6 last week which worked great. XBMC installed on it

Here were the exact steps I did. I'm very precise here, forgive me

1. Installed Java JRE from http://www.java.com because tinyumbrella requires it and I hadn't installed until now
2. downloaded tinyumbrella-4.21.11.exe from thefirmwareumbrella.blogspot.com
3. totally disconnect ATV2 power/hdmi from TV
4. connect power cable to ATV2, waited 20 secs
5. connect micro USB from ATV2 to PC
6. Waited a while for iTunes to come up. Closed iTunes.
7. Ran tinyumbrella-4.21.11.exe - it immediately recognizes ATV2, Single clicked 'Connected Devices->Apple TV' in upper left of app.. shows 'The device is connected' at bottom, and automatically shows info about it at bottom of app (ECID, firmware rev, serial# etc)
8. Clicked 'Save SHSH' button at upper right
9. App shows that various firmware shsh (AppleTV 4.2 (8C150), AppleTV 4.2.1 (8C154), AppleTV 4.3b2 (8F5153d), AppleTV 4.3b3 (8F5166b)) are being saved, progress meter on bottom moving.
10. After about 1 min 50 seconds, progress meter completes.

After it's all done, under the 'Log' tab it shows this text below. SHSH blobs are saved locally to C:\Users\<user>\.shsh folder and also to Cydia servers.

02/20/2011 21:24:18.713 Caching shsh files...
02/20/2011 21:24:18.721 Found [0] shsh files to cache...
02/20/2011 21:24:18.726 Cached [0] shsh files
02/20/2011 21:24:18.729 You are using the current version of TinyUmbrella.
02/20/2011 21:24:18.732 Loaded History...
02/20/2011 21:24:19.173 Device connected: Apple TV
02/20/2011 21:24:19.184 Loaded History...
02/20/2011 21:25:14.511 Started saving SHSHs for [Apple TV]
02/20/2011 21:25:18.186 You have saved your AppleTV 4.2 (8C150) SHSH locally and the request was sent to CYDIA. This means that CYDIA DOES have your SHSH. Do NOT bug semaphore about the Cydia home page showing this version.
02/20/2011 21:25:18.186 You have saved your AppleTV 4.3b2 (8F5153d) SHSH locally and the request was sent to CYDIA. This means that CYDIA DOES have your SHSH. Do NOT bug semaphore about the Cydia home page showing this version.
02/20/2011 21:25:21.028 You have saved your AppleTV 4.3b3 (8F5166b) SHSH locally and the request was sent to CYDIA. This means that CYDIA DOES have your SHSH. Do NOT bug semaphore about the Cydia home page showing this version.
02/20/2011 21:25:23.209 You have saved your AppleTV 4.2.1 (8C154) SHSH locally and the request was sent to CYDIA. This means that CYDIA DOES have your SHSH. Do NOT bug semaphore about the Cydia home page showing this version.
02/20/2011 21:26:06.413 This device isn't eligible for the requested build.
02/20/2011 21:26:06.428 CYDIA DOES NOT HAVE YOUR SHSH FOR AppleTV 4.1 (8M89) THERE IS NO WAY FOR YOU TO GET THEM. SORRY. YOU ARE JUST TOO LATE.
02/20/2011 21:26:06.444 Finished saving SHSHs for [Apple TV]
02/20/2011 21:26:06.506 Caching shsh files...
02/20/2011 21:26:06.506 Found [4] shsh files to cache...
02/20/2011 21:26:06.522 Cached [4] shsh files