Augghh, I'm so frustrated.:sob: The machine was doing just fine and now I can't embroider a thing without VERY severe bird nesting on the back. It's a Brother PE-770 (embroidery only machine), only a couple of months old. I'm absolutely sure it's threaded correctly; bobbin wound evenly and going in the correct direction; bobbin is correctly in the caseing/spring tension correctly; using good thread and correct stabilizer. Removed and cleaned the bobbin case and am sure it's re-installed correctly. Also put in a new needle. The top looks just fine, but the bottom is just a huge mess of tangles and birds nest so badly that when monograming, I can't even get one letter before the machine jams because the nests are so bad. The tangles and bird nests are of the upper thread. Any ideas???