Don't think you can update or downgrade to 4.3.3 now unless you have your shsh blobs and if you don't know what shsh blob is then you probably don't have it. I believe you can only upgrade to iOS 5 or maybe 4.3.5 (not sure).
Considering there are instructions on adding repos, it's a safe bet to say that Cydia has blobs saved. But I do not see TinyUmbrella running. Download and run TinyUmbrella, make sure the ISPW file is for your exact version of iPad, and try to shift restore