I understand that you haven't jail broken it yet (as I know that iOS 4.3.5 on the ipad2 is not jail breakable).
It's just that jail breaking an iPad and saving blobs are two different processes and you don't have to be jail broken to save your blobs. To save them, download the program Tiny Umbrella and, with your iPad connected to the PC, run it. It will save all the blobs that are save able for that iPad.
See this thread for a good breakdown on SHSH blobs:
http://www.ipadforums.net/showthread.php?t=59291
Since the two processes are different, we always recommend that people save their blobs whenever they can, even if there is no way to use them. Cause, you never know. I would recommend you download Tiny Umbrella and start saving those blobs today(!).
I'm not sure if the window is closed for iOS 5.1, but it's worth a shot to run it (today!) to see if you can get them. You can definitely get the blobs for iOS 5.1.1 today, as the newest version of Tiny Umbrella has just been released to get them. It's version number 5.11.00.
Unfortunately, again, without those blobs, there is no way you can jail break your iPad. There is no jail break for iOS 4.3.5 and the only other jail break for the iPad2 is on 5.0.1, to which you can't upgrade. So, hang in there - we keep hearing rumblings that a jailbreak for 5.1 is just around the corner. You'll have to wait and see what develops.
Marilyn
