You might be able to see something happening if you use Firebug or whatever “developer tool” your browser has (usually opened by the F12 key), or looking at the page ‘source’.
You can also try your kiwitrees error logs (administration > logs and filter for ‘error’ type).
There’s also a possibility your web host’s error logs might have a record.
But beyond that it’s impossible to guess without access. Happy to look if you want to give me temporary access and “how to reproduce” steps.