Vista - Scanner problems

My HP Scanjet 5530 worked perfectly on the first three pages of a four page
document, i.e. it produced the pages in Word in all colors and with exact
detail, so that I could Save As in the appropriate Folder, which contains
many files of similar documents.
On page four the Scanner ceased to produce the documents in color and some
of the data was garbled. I then used the Picture instead of the Documents
button when the document was properly reproduced, but when I want to Save As
it produces the proper folder but it shows it as empty!
HP suggested I try the latest driver, but this did not change the
performance one iota.
Which hardware is at fault - my computer or the Scanner? If the latter any
suggestions how I can overcome the problem that when I click on Save As I
get an empty folder instead of the one I have!