Firewatir click button only flash's

Dear all,
I’m making a test for a website.
This website works on IE(internet explorer) and FF(firefox), IE works
and now the FF test is being developed.

A button has to be pressed. When calling the code, I only see that the
button gets the “flash” but nothing happens after this.

Button code HTML:

Nu registreren

button click code:
@ff.div(:id, ‘registerNowId’).click

Has anyone ever had this problem, only the flash but not the action?

Cheers,
Flaming F.