What glue would you recommend for the iron-on method?
Also, when you apply glue on the veneer, how do you keep it from curling up?
How long should and could I wait after applying glue before ironing?

I recently veneered a pair of small cabinets and was very upset when the veneer bubbled back up several days later. I used Titebond I and spread it on the MDF with a scraper, careful to ensure a thin even coat. While the glue is still semi-wet, I ironed the veneer with the iron on high. A couple of hours later, I flooded the surface with boiled linseed.

I can think of several things I might have done wrong in the above description, but would appreciated your help to ID them.

Wrong type of glue?
Need glue on MDF and veneer?
Ironing too soon?
Iron too hot?
Not waiting over night before applying finish?

thx,
Gar.