Table header disappear when exporting to pdf

Hello Adobe Community I'm using Indesign and have created a table, the upper cells row I have done as Header and introduced an image in each cell. The header repeats in each single page after and this is fine. The problem appears when exporting in pdf where the header appears only on the first page and not on the followings. File was created with CS3 first than converted to the last indesign. Thanks alot for your help. Beppe