Scanner not available, OR scan will not save to file

Question

Hello,  HP M1212nf, using HP Director/HP Scan 1.1, on an iMac running OS 10.6.8.
On the control panel, the Ready light is on, the Attention light is off, and the  Toner light is blinking.  
I try to scan a document, but get "the scanner is not available" message. USB connections are good...
Occasionally, it does scan successfully. But then when I try to save it as a file, all steps work beautifully -- PDF/JPEG/etc, name file, choose destination -- but the supposedly saved file is nowhere to be found. (Spotlight doesn't see it, and it's certainly not in the destination I chose.)
What's going on, and how do I fix it?!
Thanks in advance for help!
Ch.S.

Answer 1

 > Maybe if you go for another walk to the mall and pick up another sack of potatoes, the printer will start working
 > again, if you get a bag of carrots too, it might continue working. 
    I have enough potatoes and carrots, thanks...   ;-)
Thanks ever so much for your perseverance in helping me with this!!!
> Try and print a hardware self test on the printer to find out if it is a hardware or software issue.
> Printing Information Pages.
     The config pages print beautifully, although the toner light (yellow) is flashing.
   > When you get this error message, are you still able to print?
> Is there any lights flashing on the printer before trying to scan?
    The scanning problems (not being able to save to file, and sometimes, “scanner not available”) are not affecting printing. The print function works beautifully, even though the machine seems to think its toner level is low (flashing yellow light).
> Make sure the printer is connected directly to a wall outlet and the USB cable is connected directly to the
> computer.
> The USB cable shouldn't be longer then 6 feet. Do you have another USB cable to try?
     Printer was connected through a power bar. I changed it, straight into wall socket. 
I do have another USB cable, have replaced the one I was using with the other one.
  Same problem persists: “save as PDF” refuses to work: the file seems to disappear, and Spotlight doesn’t find it anywhere.
    The only work-around I have found is to choose “e-mail” instead— this puts the PDF into an e-mail, from where I can move it to where I need it. This solves the problem, sort of, but it’s a tedious long way around.
> Reset Printing System:
> Note: This will remove all printers in the print and Fax/Scan, any printer removed can be re-added later by clicking > the plus (+) symbol.
> 1. Click the Apple icon (  ), and then click System Preferences.
>  2. Click Print & Scan.
               It’s called Print and Fax on mine.  
> 3. Right-click (or Ctrl +click) in the left panel and then click Reset printing system.
> 4. Click OK to confirm the reset.
> 5. Type the correct Name and Password. 
> 6.     Click OK to reset the printing system. The Print & Fax dialog box shows no printer selected.
> Then add the printer from the same window.
> Click the + sign, select the printer from the list, click on the add button.
       OK, all done. Closing SysPrefs and trying again.
Behaviour is largely the same.  Two issues:
1-  Now and then I get “scanner not available” message. Turning off the printer and quitting HP Director, then turning printer back on and restarting HP Director, usually gets past this “unavailable” issue— it scans successfully. Sometimes it takes more than one off/on quit/restart cycle to banish the “unavailable" message. This is not a faulty cable or connection issue. What the *$%^%# is it?!
2- scanned file won’t save— BUT here’s some progress: if I save under a different name, like “test”, there’s no problem. If I save under the name I want, which for the current page is “Arrival Va 1/2”, it disappears instead of saving. Could my problem be this simple: In the "save as file" dialogue box, I’m not allowed to use a symbol like “/“ as part of the file name????? 
If that’s it, I can work around it, just saving the file and changing the name afterward. 
I hate to think, after all this hair-pulling (and I don’t have that much to start with), it might be as simple as that!!
But it seems to be: saving as “Arrival Va 1/2” doesn't work, but saving as “Arrival Va 1 2” does.
 Even if that’s it, I’d still much appreciate your thoughts on the “not available” messages...
Again, a million and a half thanks!!