fabric gets stuck and thread is clumped together underneath?

When I am sewing, the machine will make 3-4 stitches, then it will stop. Even if you press the foot pedal, the machine hums but won't move. Then I try to pull the fabric from beneath the presser foot, and it is stuck and connected to the machine beneath the presser foot by about 4 thicknesses of thread. The machine ran fine until the whole "needle holder" fell out of the machine tonight. My dh reinserted it, and now we have this problem. I have checked to make sure the needle is in facing the right direction, and I have replaced the needle with a new one, and I have adjusted tension. The operator's manual does not address this problem. This is a Brother XL-6452. The Brother machine I had for a few days just before I bought this machine did the same thing, and when I called customer service, the rep told me that she had never heard of anything like this and suggested I return the machine to the store for a refund, which I did, and then purchased this machine (same model #), and I have had my current machine for six years and have experienced no problems at all until today. I have no repair shops within 50 miles of my home, and if I can fix this myself, I'll be elated!