I have a friend who visited before Christmas to photograph some models ( metal

) using flash. He has a Canon 300D. He also took pics using Stevies D100 and my X. So impressed with the flash setup he ordered a two head studio kit.
When comparing the pics from the day all the 300D have a blue cast, whereas D100 and the X are fine. Today the flash units arrived he has had a bit of a play. Again all showing a blue cast. Outdoor shots taken immediatly afterwards are fine with no cast.
1) Has anyone experienced this, and have a solution.
2) Does anyone have a link to an online manual that I can download and read.
Thanks in advance.
Don