check box changing shape

HI,

I am having issues with check boxes created in Indesign and saved to interactive PDF.

The files has been fine and used for most of last year. I have adapted these and the check boxes which are square shaped in ID appear as double the original height rectangles in acrobat.

The SWF preview in Indesign show these boxes the correct size/shape.

Any ideas?

Screenshot of ID file.....

Screen shot of PDF......

Thanks