The supposed cause of tension, as you would imagine, is money. Ivana, per her marriage to reality show star Donald Trump, has a townhouse on East 64th Street, a flat in London, houses in St. Tropez, as well as the Palm Beach estate at which she currently resides. Conversely, Rubicondi is described by the Post as "penniless."
Donald, who we hear is actually paying for the entire shindig (it's being held at his Mar-a-Lago club), is adamant about protecting the assets Ivana stripped him of and thus had his lawyer draft a prenup, which Rubicondi has yet to sign. The prenup is said to be the cause of the St. Paddy's Day blowout, which ended when Rubicondi was briefly handcuffed but not formally arrested.
On the off chance the wedding actually is canceled, the couple will have some money to return: while the Palm Beach Post says Getty shelled out $250,000 for the rights to "exclusive" photos of the ordeal, the Post claims that OK! actually bought the rights for $1 million. We have a hard time believing that Ivana Trump's wedding to a no-name, gold-digging Italian actor would command 10% of the cost of hypothetical $10 million Brangelina twins pics, so we're gonna go with the Palm Beach Post on this one. Even though that number still seems like $250,000 too much.