Column´s Size

HI,

I´m with a big problem.
I have two files with the same hierarchy.
In the first one, I set the column´s size with 30px. In the another one a make the same, but on IE it shows different. One with 15mm and the other with 5mm. But when i use Firefox, it shows fine.Both with 5mm.
Someone has an idea about this?

Thanks

Alexandre