Data report control's position

Hello
im developing a report with Microsoft Data Report. My report is landscape and i'm using zero to left, right, botton and top margins.

The report accept lines in any position, but don't accept text boxes in some places in report.

i'm sending the screen captured that show the limit of lines and the limit of text boxes in report.

When I try allign to right (end of line) the text box, i receive the message: "Report width is larger then the paper width".

My question is: why can I place lines in any position of report but I cannot place text boxes in any position?

thanks
Daniel