Unable to adjust fluid box slider and percentage

While we creating a layout for captivate using fluidbox initially i can able to create any required width and height fluid boxes. but once we started the project and after words we unable to change the fluid
box elements width anymore. i have tried using the nob like shown in the image.. and also using the position tab by giving % values and pixel values. but the new values doesn't change in the fluid box. it might be small thing which we missing..

I am not able to move the divider after a certain percentage. even I tried to give percentage manually.
if you see the GIF i tried to change the percentage 37% to 10% but it goes back to 37%.
Thanks for the support
