Capybara + Selenium: save_and_open_page shows button, but capybara can't find it

Question

My capybara test includes these lines:

click_button "SHARE"
fill_in 'Email Address', :with => @user_two.email
save_and_open_page
click_button 'CONFIRM'

the share button would make a modal visible. Filling in the email address text box of this modal seems to go off without a hitch, but I receive the following error for the button

 Capybara::ElementNotFound:
   Unable to find button "CONFIRM"

However, when I save_and_open_page, the button is visible.

I've tried switching to

page.find("#id-of-button").click

but Capybara can't find that either.

It's interesting to note the save_and_open_page shows me a page where the field for email hasn't been filled in.

I think I might be missing something basic about how save_and_open_page works because if that is the page Capybara is seeing in its totality then these errors make no sense to me...

edit: Modal view code

.title.aaux
  Title
.content
  .line-separator
  #intro
    Enter Email:
  = form_for(patient, url: {controller: "dashboard/patients", action: "share_with_user"}, method: :post, html: {id: "share-patient-form"}) do |f|
    %fieldset.bordered
      = f.text_field :share_user_email, placeholder: "Email Address", class: "aaux form-control"
  .line-separator
  #button-row
    %button.btn.btn-success.aaux.pull-right#confirm-share-patient{type: "submit"}
      CONFIRM
    %button.btn.btn-cancel.aaux.pull-right#close-modal-share-patient
      CANCEL

edit: source code generated for button

<button type="submit" id="confirm-share-patient-button" class="btn btn-success aaux pull-right">
CONFIRM
</button>

Answer 1

I changed from selenium webdrive to capybara-webkit, and the issue no longer occurred.