Are you installing this package on your own, or are you doing it through SYstem Update?
While I haven't looked up this specific package, IBM/Lenovo updates in the past require the downloading of the update, then you have to go in and manually run the setup or executable file. It is a bit of a two step process.
T61,T42(x2)T41,T40(x2),R40,T30(x2),T23(x3),T21,T20,X20,A31,A21M,600/E/X(multiples of each),770X,i1400(x2),760XL,760ED(x2 w/base),380XD,755CD,750P,360P,365X,560X,701C/CS,730T,PS/Note
I am doing that thru ThinkVangage System Update 3. >> Get new updates >> then I chose to download and install that package. It is downloading and later updating, but at the end it says the error I wrote above.