Homebrew PCBs

Hello all
After three working boards using the photo resist method I seem to 
have run into a problem.
I was using fotoboard 2 pre coated laminates
Sodium metasilicate Developer solution (first batch was diluted 10:1 
but found developed far to quickly so I am now using around 15:1 and 
20:1 dilution to slow down the developing process)
Feric chloride etching solution mixed 1:1 with water

After exposure for a minuite (more than 2 mins causes the developer 
to completly remove all resist), I developed the board and all seems 
fine. I get a good positive image of the artwork from transparent 
film to the board but when I try to etch the board nothing happens.

To test my etchent I made a quick test using copper clad board and 
an etch resistant pen, this worked no problems at all, a perfect 
board.

I've tried both my first batch of developer (10:1 dilution) and my 
second batch (20:1) but both gave the same result. 

Anybody have any idea where I am going wrong

Best regards
Tbone