After 1 year of trial and error with CFL's I think I have figured it out. Now before you ask why not use an MH and HPS? Where I live i cannot find them.
My grow setup consist of a 2 partition box. Top section is the clone/veg room. It consists of 5 100W CFL in cool white color. My plants grow...
What kind of lights are you using....this problem is common with a flowering setup with a low lumen output. I experienced this same problem and upped the lumen out by double and had great results. Are you using CFL lights?