The recent findings of Watanabe and Logothetis on dissociating attention and awareness are interesting
Watanabe, M, K Cheng, Y Murayama, K Ueno, T Asamizuya, K Tanaka, N Logothetis (2011) Attention but not Awareness Modulates the BOLD Signal in Human V1 During Binocular Suppression. Science 11 November 2011 DOI: 10.1126/science.1203161
but a more conservative interpretation might be that when there is divided stimulation and divided attention, stimulation and attention both contribute to awareness (of stimulation), with attention selectively enhancing the effects of the stimulation.
Harnad, S. (1969) The effects of fixation, attention, and report on the frequency and duration of visual disappearances. Masters thesis, McGill University.