Dont be afraid to adjust your tension..once you figure it out it is liberating. Here is a GREAT video on tension and IT WORKS!! listen to it over and over again - I still watch it. Makes alot of sense..
http://www.youtube.com/watch?v=Q1mRhcquZTM

I hope this helps.

If you are using a batting that is thin like Warm and Natural, it is difficult at best to avoid the "pokies" top or bottom side. I would suggest using a poly or poly/cotton blend. Also, using a polyester thread will be easier to accomplish using different thread colors.
Also, if you are using the machine as sit down machine, you may be moving your fabric too fast. If you are using it on a frame, you may be moving the machine too fast.
If you are getting railroad tracks or eyelash effect on back of the quilt, you are going around curves too fast. Just like driving a car, you must slow down on the curves.

I am fairly new at FMQ so I do tend to move the fabric too fast at times, and I am using Warm and Natural batting. Thanks for all of the advice.

I have asked this question many times and, although I have learned a lot, I have yet to solve this is on my own machine. I too have concluded that some machines just can't FMQ.

Enjoyed the video at link (but wished there were more closeups). Thanks for that.

Some machines work better with some threads.

Microtex & topstitching needles have sharp points that pierce woven fabrics better than universal. giving better balance of top and bottom threads. Topstitching have longer eyes and deeper scarf allow the thread to move with less drag, therefore more consistant stitches.

Don't know if you are able to do this on your machine but, if you are, it is an easy way to get the tension right. Here goes. Make a sample sandwich and set the machine for a wide zigzag stitch and sew about 3 inches. Check out the quality of the stitch tension. Adjust the upper tension till you don't see the bobbin thread. If you can get it right with the zigzag stitch it will surely work for a straight stitch. If that doesn't seem to work, try one of the Magic Genie teflon washers in the bobbin case. I use one all the time, better safe than sorry.

I never use a different color in the bobbin because of this. It's almost impossible to keep the "pokies" from one side or the other.

My machine just has a straight stitch but I just googled the washers and am definitely Going to order some..thanks

I had a friend years ago and that taught me to adjust the tension on my machine, top and bottom. I'm so glad she did! I can do things successfully that I could never do before. Another thing she suggested is to buy and extra bobbin casing and mark it. I now have one that is my straight stitch/normal casing and one that I can mess with the tension on for machine embroidery, unusual fabrics or whatever. That way I always have one that is ready to go for straight stitching.