prints gray area

Hey,
I've been using photoshop for ages just doing random basic stuff at home and I've never had this problem before...What happens is when I have a white background on the screen with (for example) black text on it, it will print out with a light gray background instead of the white background that appears on my screen...I don't know if its a printer properties thing or just my crappy printer itself
Any help would be much apreciated
Egg

If the background was truly white, there would be no colour information for the printer to put any colour there. Check to see that the background is really white and not a very light grey. Open the Info pallete (Window> Info) Choose the eyedropper from the toolbox. Hover the eyedropper over the background of the image. Look at the CMYK values in the Info pallete. If the background is truly white, all the values will be zero. The values will be something else if there is colour there.

yeah the background is white, all the CMYK values are all at 0%, but the printer still prints a grey background....