Creating a growth curve for bacteria- reaching various log phases - (Jul/31/2012 )

Hi! I need to create a growth curve for my sample of Vibrio splendidus. I've done the growth curve a few times and have reached log phase OD600 readings of anywhere between 0.71-1.03, when I'm typically expecting log phase of 0.8ish. I've repeated this experiment about six times and am wondering if the log phase can start to plateau at different OD600 depending on the culture. I've been growing mine samples up in TSB+2%NaCl, but have used differenet batches of it.
Has anyone else experienced this?

Do you use the same exact size of inoculum? number of cells, UFC,...
Does the inoculum come from the same origin/culture medium with the same age, temperature, agitation speed, volume,...?
Do you get the inoculum from the log phase?

The growth curve is dependent on all those parameters