Hi everyone, I've been playing upright with a bow for about a month. I have lessons with a teacher regularly. Last week I have started doing 2 octave scales.. And went to get my bow rehaired where I'm renting it from - Kolstain's in Long Island. I came in, and the guy just gave me another bow, and the hair on it was said to be new, but played on. It's called salt and pepper as my teacher called it, because it has white and black stripes. I use Kolstein's Ultra Bass Rosin. The bow squeaks!!! It's just not catching the hair, unlike the last bow with white hair... If i tried to bow normally like I did with the last bow, this new bow just doesn't catch the string, and squeaks producing overtones...I am getting annoyed, and I have to use extra pressure to get it to catch the string, and my arm gets tired, which is the result of stress and improper technique. I got the bow saturday the 20th, and played it sunday, wed, and today - 3 days, so the hair should have gotten used to rosin already... Plus I tighten the bow pretty well. Can anyone please suggest something?