Hi keyssandi,
There may be a setting in Adpbe Reader that can be changed to get you printing again:
1. Ensure that your PIXMA MX310 is turned on and connected.
2. Open the PDF you wish to print.
3. Click File and then Print.
4. Click Advanced. Please note, the location of the Advanced button depends on the version of Acrobat Reader.
5. Select Print As Image.
6. Click OK to close the Advanced Print Setup dialog box.
7. Click OK to print the PDF.