Yes, more often than I'd like to admit. Do you have a friend that you could "buddy up" with? Sometimes, someone can see something that we can't because we are too close to it. It sounds like your seams aren't true 1/4 inch. I speak from experience on this, this 1/4 inch thing is the bane of my existence. Check that you actually have a 1/4 inch seam allowance, that your blocks are pressed well (I've started using spray starch). Another thing that can cause problems is if you constantly use the same place to cut on your cutting mat. It will make a groove and your cuts will be off.
That being said, that's what we're here for. If possible, post a couple of pictures of the offending blocks. The people here are so knowledgeable that I'm sure someone can tell you what's wrong and how to fix it. Hang in there. When it all comes together the way you want it to, you can do a "not so private" happy dance!
Michelle