Have you specifically set the line spacing for this field or text object in the inspector? Try 1.1line height and see if that affects it. Experiment with line-heights in both Pixels and Line-count.
If the users are specifying type sizes other than the size set at the layout level, this causes FileMaker challenges in rendering.
Also be aware that combining font styles such as Bold WITH Underline creates conflicting instructions in some fonts metrics, and such formatting is a bit like send all of your email in ALL CAPS.
It may be time to teach some style restraint if the results are to look professional.
Know what I MEAN?
Thanks for the feedback. I have tried various line spacing settings without success though I'll revisit based on your advice.
I have had better results using other fonts though, specifically Cambria which I think is installed with Microsoft Office. Unfortunately the house style for my client is Times or Times New Roman so these alternatives cant be used.
To try and eliminate specific issues with my development I created a new file in FileMaker with just a single text field to test this. The field format was set to Times New Roman 12 point plain. Applying the bold underline formatting to the text entered produced the same result. Not only with Times New Roman but also with Arial.
I suspect the effects Im seeing is a result of FileMaker compensating for the differences between Windows and OS X line heights so as to give a better cross platform experience.
Another thing I have noticed on OS X is the availability of all the font styles as individual fonts enabling the selection of Times New Roman Bold or Times New Roman Italic etc. Where as on Windows you can only select Times New Roman and have to use the styling to create bold or italic etc. Im wondering if this creates a pseudo bold which doesn't handle underlines and leading as well as a true bold outline.
Yes, one issue is that styled text is not rendered as precisely as plain Font-based text. Unfortunately, if the system need to be cross-platform compatible, you need to specify the generic font and then apply the FM style, even if developing on Mac.
Specifying a Mac font choice and expecting FM to render it via FM styles on Windows is just asking for problems. I see all the great Mac style-specific font options when developing, but have to pick Verdana and apply the FM Bold instead of picking Verdana-Bold font to minimize Windows issues.
And, of course, Bold style and Underline style actually change the line-height needed for rendering the text, but FM seems to still have some issues with that when calculating page breaks.
For what it's worth:
Windows 7 has issues, too.
I posted a thread recently pointing out that Times / Times New Roman in bold will not print if the text is in a field but will print if placed directly on the layout.
I was not aware of that specific problem, but do recall issues in the past where a specific system font did not correspond correctly to the metrics for the font of the same name in a postscript printer's internal memory with weird results.