The Muslims that don't like it are some Muslim viewers...not really famous reviewers or anything. Just did some more searching, and one Muslim on the Yahoo movies board says it portrayed Salidin as willing to do anything for revenge and he said the movie treated Salidin too harshly. The same reviewer said the movie helped him look more positively toward Christians though.
Based on this action in the movie, it may portray the Christians positively according to Christianity Today:
"Guy de Lusignan (Marton Csokas), a Templar who is married to Sybilla and is thus poised to sit on the throne himself, insists that God wants the Christians to slaughter the Muslim hordes. But Baldwin refuses to comply, even going so far as to hang knights who would pick fights with their putative enemies. Witnessing one of these executions, Balian remarks to a Hospitaller (David Thewlis), a member of the military-religious order entrusted with the care of unwell pilgrims, that this seems odd: "They are dying for doing what the pope would tell them to do." The Hospitaller replies, "Yes, but not Christ, I think."
This movie looks like it gives the good and bad in both sides. I am worried it will show more bad in the Christians, so I am leery of going to see this.
I don't want to waste money on pro-Muslim propaganda.
this one from decentfilms.com:
"Still, the film cross-examines the Christians in a way it doesn't the Muslims. “At first I thought we were fighting for God,” says Tiberias, “but then I realized we were fighting for wealth and land.” Oh. What are the Muslims fighting for? What were they fighting for when they captured Jerusalem in the first place?
More than once we see Muslims engaged in daily public prayers, but we never see Christians similarly engaged. Prayer for the Christian characters is only a solitary struggle with the sense of God's absence.
Despite these contrasts, Kingdom of Heaven makes an uneven effort to bring a measure of even-handedness to the religious divide. The film’s perspective, though, is ultimately more secular than religious. Even the Hospitaler, the most positive religious character, is more a spokesman for conscience than for faith per se. Kingdom of Heaven isn’t anti-God or even necessarily anti-faith, but there’s an element of anti-religious sentiment at work here. “Thank you, your Eminence, you've taught me so much about religion,” Balian sneers after the Jerusalem Patriarch has alternately suggested abandoning the Christian populace of Jerualem to slaughter or converting to Islam and repenting later as a means of saving their necks."