I would take a bit of a break, then return to your machine. If you can figure out where that 1/4" seam is on your machine, it does make your quilting life easier, as you don't have to struggle to get your blocks to fit together.
First, don't make a practice block to figure the seam out, use the following technique:
http://www.quiltingboard.com/tutoria...ce-t89997.html
I have an expensive machine, with a 1/4" piecing foot (which was also expensive!) and was having problems. I did the test above and found out that I had to move the needle over quite a bit to get where I needed to be.
A thinner thread also helps, but C&C is just fine too. If you do decide to try a thinner thread (in your next project), you will need to redo the test above because the 1/4" guide might change.
If your quilt has all the same block, then consistent is going to work just fine, but more complex quilts will go together easier if you use the correct seam.