I tried the dim quiet room for our 10 month DD, and that never seemed to work. Just this past week I tried giving her a small toy for her to hold and play with when we nursed, and that seemed to work really well! I WOH full time, so during the week, so I have the most problems with evenings and weekends (mornings and middle of night she nurses just fine). She's busybusybusy during the day too.
If she's waking screaming, it probably isn't just a hungry/wanting to nurse thing. It may be that she's in pain if she's getting her molars like you mentioned. Or, possible ear infection (has she been sick recently)? We noticed that for our DD at least, that if she woke up that frequently and screaming, that it was from pain from an ear infection and/or teething. Have you tried teething tablets, tylenol, or motrin? Or, doctor to check her ears out if she's been sick recently? I know a lot of people don't like to give medicine to their babe, but Motrin has been a lifesaver with our DD when she's teething. We only give it to her when it's really necessary because we don't want to rely on it, but it's worth it sometimes!