midadi-san,
indeed you are right, reference letters (with all the requirements, i.e, on a company letter head and so on) from you previous employers are required. however, what i meant to point out was the reference letter from your 'current/present' employer.
as in my case, again, based on my personal experience, they didnt ask for a reference letter from my current employer (like you, otherwise i'd be in trouble too). instead, they just needed a proof of my current employment status, thus, copy of my first page contract was required.
nonetheless, do not quote me on that as what i have learnt is that the recruitement process can be vary from place to place.
moreover, later on after you definitely get the job (fingers crossed), a so called 'letter of confirmation of resignation' (or a release letter from you present employer, yet again with all the requirements) will be required to be produced/submitted upon joining/arriving in dubai.
cheers,
skyisthelimit