The handling of text fields is done in the form builder, of course. I'd have to look to see whether knocking out spaces would work because there are a whole slew of widgets that use the basic text data type. For the datatype/widget pair text/text I think it would make sense to disallow blank entries, no doubt about it. So perhaps it should be a widget check not datatype check but the form builder's built around the notion that the datatype implementation routines do the checking not the widget implementation code ...
Dave ... I looked at the ad_form code that executes the validation block and all form element values are set before that block is executed.
Can you e-mail me or post here the code that failed?