If its not too late or others who have the same problem.
Check this out: www.mae.ro You'll find the list of countries and all the regulations.
"The above-mentioned citizens are exempt from the Romanian transit visa, however they are not exempt from the obligation of fulfilling the general conditions of entry, provided for in article 5, paragraph 1, from Regulation 562/2006 of the European Parliament and of the European Council, dated March 15th, 2006 – The Schengen Borders Code (they must hold a valid travel document, supporting documents in the sense of the purpose and conditions of the trip, as well as be able to make the proof of appropriate financial means for the entire period of the transit through the Romanian territory);"

But it is right, they wont ask much and anyhow you must have a ticket back from an other country in the EU or close by and that should be ok!

Hello. You do not need a return ticket. Citizens of Australia coming to Romania for tourism purposes can stay up to 90 days as per the Romanian low. You do not need a return ticket but you may be asked for a proof that you have some services booked for your stay here (such as a voucher). We are a travel agency, if I can be of further help you could e-mail me on ana@holidays-partner.eu
Have a good, safe trip, Ana Irimia

Hi Star,

Officially you would need a passport valid for 6M, but I worked with thousands of tourists (American river cruises) and no one ever was checked.
If you need any more assistance feel free to contact me!

Monika
www.exclusivetours.ro