i have been working on a quilt for a monthw/no problems until 2 days ago.suddenly i'm getting "tangled upper thread ,bent needle"warnings. can't tell you how many times i've re-threaded,changed thread & needles to no avail.i'm tearing my hair out !!! justgot it back from the shop after 4 wks!it was great til now . any help would be appreciated SO much.don't want to have to give it up AGAIN.thanx for any help you can give me