Help! Quantification of total RNA, equal loading

[Soo-Hwan Kim]

I found difficulty in loading same amount of total RNA in wells of RNA gel.
I isolated total RNA from different tissues of plant and checked the quality 
of the RNA by seeing the ratio of A280/260
It seems that the quality is good because They ranges 1.8-2.0.The problem 
arose when I loaded them and cheched the amount by EtBr staining. I loaded 
same O.D of each RNA for different tissues.I stained the gel with EtBr to 
confirm equal loading of the RNAs.What I found was different amount of RNAs
in each sample(tissue) judging from the comparison of rRNA intensity.
The differences were up to 2 times. I need to get equal loading because I 
am working on the comparison of expression level of some genes.
Do I need to adjust the amount of the loading and ignore O.D260 to get equal 
loading in EtBr staining or Do I need to depend on O.D value and ignore staining
intensity? I need help.