DIG labeling - southern blot

[rashmis248 at fastmail.fm]

I have been trying to get  a decent southern using the 
DIG  labeling system from Roche.THough I get a good labeling 
efficiency when I check my probe (labeled using PCR)when I 
probe my blot I end up with a very dirty background
My bands are visible though.
COuld it be due to Et bromide ??
Or is it because I am not using a very efficient technique when actually 
incubating the membrane with the substrate(CDP star)in the final step.
I try to make sure there are no wrinkles or air bubbles...but...:((
HElllp!!

http://biowww.net/mynews/tree.php?group_name=bionet_plants&begin=0