Transparent raster images and plotting

Hi all,
I just wanted to know if this is normal and that there's no solution for this. We use raster images in our files quiet often, like tiffs. So in our department we know that we should not set the images to transparrent cause it kills the plotter or even the printers. But, we often get drawings from subcontranctors or other departments and they don't know that, so we will try to run a batch and it will clog the printers for eternity.
So, the question is, is it normal for the transparrent raster images to clog the printers? Tiffs are all under 1mb, and we switch from paperspace to model space, no difference there.

We are using raster design and Cad04 and using any kind of plotter.

Thanks for your help.
Viktor.