Thanks was really hoping I could do something as I cant replace some of the low res stuff I would like to use.

If you un-check "resample image" the file diamentions will shrink giving you the a smaller file size at 300 dpi. So if the file was 8" x 10" at 72 dpi it will be 2" x 4" at 300 dpi which will give you a good resulotion for print. Unfortunatly you get a small picture.