I thought I'd post this to help anyone who encounters the same problem, but also in case Rockettheme might consider changing the way input styling works (to save me having to hack the core code!).
The current method of input styling checkboxes and radio buttons is to place the actual element -1000px right or left of the page.
This causes a problem with Chronoforms, which places error messages above the checkbox/radiobutton.
The solution I used was to edit gantry-inputs.js and replace the instances of e.setStyles({position:"absolute",left:"-1000px"}
and
e.setStyles({position:"absolute",right:"-1000px"}
If I modify gantry-inputs.js, will it be updated with the next update of Gantry?
In other words, is it a core hack and shall I introduce it after each upgrade?
When we release upgrades template files will change and you will have to reapply all your changes again (that's if you can remember where they all are). If you keep your changes in a separate Custom CSS file you'll have no issues upgrading.
I appreciate your reply and support.
I can easily create customs CSS files (I have successfully done it in the past).
I have some basic knowledge of CSS, PHP etc.
However, I totally don't understand language of gantry-inputs.js.
Can you point out what exact wording shall I introduce into my custom css file to overcome the bug?
As I wrote, you will have to use Firebug to find css definition you need to change and override it in custom css file. Forget about gantry-inputs.js completely and focus on finding that css using Firebug