You should be able to access the scanner directly by typing the name of your printer into Spotlight.
Once the Printer dialog turns up, click on Scanner to bring up the scanning screen. Then (if available) click on "Show Details".
You will see a range of options, including a tick box next to "Combine into a single document".
That should take care of things.
By the way, how did you previously access your scanner?
When I try Spotlight I get the manuals, the HP webpages but no icon for my printer. Prior to the last update of Lion there was an icon in my dock that gave me a great window where I could edit scanned cdocuments - quality, rotate.After the update that icon gave me an error window "HP Scan cannot be opened becasue of a problem" Now when i select the scanner via System Preferences there is a lengthy warm-up process. I note there is an option to combine a PDF file into a single document - I had not noticed this before.
Below is something that may be relevant from teh error thread
Dyld Error Message:
Library not loaded: /Library/Image Capture/Support/*/HPScanProfiles.framework/Versions/A/HPScanProfiles
Referenced from: /Applications/Hewlett-Packard/HP Scan.app/Contents/MacOS/HP Scan
Reason: image not found
Oh dear. I thought all was good but now my iMac will not see the scanner at all - not through System Preferences, image capture, preview or the HP Scanning icon. I get the message "An error occurred while communicating with the scanner". I have uninstalled the Printer (twice) and allowed the system to reinstall itself The latest software on the HP website is date July 2011