Fotospeed FD10 - Thin Negatives

I have recently began Developing film at college using FD10 developer. I have noticed that after 10 1/2 minutes at 20C in the developer the negatives are thin and not very contrasty.
Has anyone else been having these problems with this developer or is it just me?

Andrew

Edit: I forgot to mention that the film I've used is Ilford HP5 plus

It would help to tell us what film you used.

There is a thread about the times given for FD10 developer with HP5 Plus being too short on the film and darkroom users forum.

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=3199&highlight=FD10