Both my kids started having sleep trouble at this age because of eating, crawling, growing, and teething all at once. I know how I feel after pushing my muscles while exercising; I can only imagine that they feel that way to them too. Add that to growing pains, teething pains, and adjusting to new foods and you've got a pretty achy little baby. After a few months and a few teeth both of mine started sleeping better again. (She whispered hoping her 8 month old won't hear her and start waking up again.)
On another point, I have no experience keeping my kids in my room. My first slept in his own room from night one. My second might have, but her big brother wouldn't hear of her sleeping anywhere but the crib in their room. All has gone well since. They've never really bothered each other.
I do have a friend who had trouble getting her son to sleep through the night. Her daughters all had by 6 months and had gone to their own rooms. He on the other hand was a year old and still waking up regularly at night. She said she finally got fed up and put him in his room. It worked like a charm. He slept through the night on the first time. Mom and Dad were the ones waking him up. Hey, anything is worth a try. Just try not to get him at every whimper, my kids "talked" in their sleep from an early age. I had to train my self not to get them if it wasn't a full cry.