If you expect that some of the users will be using browsers that have limited capabilities, you need to consider the limitations of the lowest common denominator and design your forms accordingly. Alternatively, if your organization uses browsers that support XHTML, you have more options in laying out the form design.
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Specify a page size to ensure that the HTML4 transformation (for Netscape Navigator 4.7.x) displays all static objects properly. Otherwise, enough space for fields only will be reserved when the form is rendered.
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Objects or portions of objects drawn at negative grid coordinates are not displayed. For example, if you draw an object starting at the vertical grid coordinate -.50, the portion of the object from -.50 to the inside edge of a 1/4-inch margin will not be displayed.
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Allow enough space around fields to compensate for the visual degradation that may occur in a low-end browser. For example, in some browsers, check boxes and radio buttons are displayed larger than they were designed.
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Any left alignment of data may not be maintained when a low-end browser is used to view the form, especially if users alter the default fonts associated with their browsers.
See also 

Working around web browser limitations