This is a common problem with many printer and paper combinations, I have found. The light you view the images in can also affect this - i.e. a print will look purplish in under one light (e.g. flourescent) but look OK with another (e.g. daylight).
You don't say whether you are printing color or black and white images/text. If you are printing greyscale images, I'd recommend specifying "black ink" in the driver. This forces it to only use the black ink. Otherwise, you may be getting color ink trying to approximate black.
If this doesn't solve the problem, then it is definitely the light or paper that is causing the problem (otherwise, how can a greyscale image printed with black ink look purple?). One thing you could try under this condition is to change the image to a color image and then use the "colorize" tool that some image editors have to give it a subtle color cast that will counteract the purple cast. For example, I have colorized to a faint dark-blue color and it has come out looking black - in Colorize dialog, use color 170, saturation 3. Gives a slightly blueish image, and forces use of color ink giving a inky/blue-black color.
If you are printing color images with some black in them that looks purplish, I have sometimes found that this can happen as you get towards the end of a color cartridge - i.e. on my Epson 1280, if the color cartridge (only one combined cartridge on the 1280) is almost out, the color can get purplish. There is no solution under this condition, except to get a new cartridge.
