I don't grow poppies but if you can't get them going indoors the reason may be that they need sowed outdoors in fall. Poppies are re-seeders and that is good indication that they drop in summer/fall and germinate in spring :)
If you don't want to direct sow maybe you can try the winter-sowing method....see "Winter Sowing" forum for more. W/S poppies worked for many :)

Good luck!

Vera