We are with Fiserv, but that fact should have no bearing on online sign-up. Technically, we don't have online sign-up, as nothing is signed. On our site, we simply have a process involving a series of pages that all have one goal - make sure that the customer needs to go through the process to reach the internet banking site. In other words, they need to review and accept the discloser. Since an actual signature is not required, other than the one secured when the checking/savings account was opened at the branch, the process has all the required elements.
So, it may be a fact that you cannot do 'true online sign-up,' but it all depends on the definition of 'true online sign-up' as interpreted by your IT person. Internet banking is simply an access method that is covered by new account disclosures. A disclosure review is posted as customer’s access their accounts in this manner, along with education material and specific warnings, e.g. email security, etc. A signature is not required.