No, I don't eat a lot of dairy. I eat plain yogurt a few times a week but it doesn't give me any problems. I don't have sinus problems. The only time I felt stuffed up while consuming something was when drinking red wine a few month ago. It started happening out of the blue (didn't have problems with red wine before) and it lasted for a month or two (immediate congestion as soon as I started drinking it). But I am OK now, I can enjoy a glass with no problems now (not sure why it came and went, I thought I must have developed allergy to sulfites but somehow it went away on its own).
The congestion I feel while drinking juice is different though, it feels like my saliva thickens up, it makes swallowing a bit harder, I don't know how else to explain it. Also, later in the day I may feel something sitting deep in my sinuses (btw my nose and my mouth where you can't get rid of it either way) and that eventually comes up my nose (clear mucus).
I got the Green Star juicer. I seem to get pulpy juice though, I thought it was supposed to give pulp free juice. Anybody else?