Are you printing checks to a laser printer or a dot-matrix printer? What is the layout of your form (adv/adv/check or check/adv/adv or another)? I presume it's adv/adv/check.

It may be that you have too many detail lines reserved for your advice, and based on the section sizes, the advice sections as a whole are too big and thus your check goes to the top of the second page. The solution in this case is to edit the File / Specification Options and reduce the Max Details number. You can preview the spec within the designer to ensure that everything fits on one page, and then print to paper to ensure that it aligns with your pre-printed check form.

If you have a laser printer, there is a top margin reserved by the laster printer driver. It may be that you have a pre-printed form that has information you want to print in, within the laser printer margin. You might be able to nudge fields higher within the first advice section (highlight and use the cursor key to move up), even so that they are partially underneath the advice 'grey' section indicator. But there are no guarantees that you can get the alignment you desire - the solution may also mean that your forms won't work on your printer due to the printer's margin.

You should verify that all the section heights (header, detail and footer) for your advices indeed match your pre-printed form.