There was an interesting story in today's Gulf News about the fact that many ATM's in the country aren't in a position yet to collect the new Dhs. 500 bank notes (click here for the link). The story talks about how banks are being implored to accept the new currency and that they're greatly inconveniencing the public at large.
Now knowing banks, I'm sure no bank wants to stop accepting cash and the problem is a lot deeper than is apparent to most. From what I know, many banks received very little notice or time to adapt their systems to accept the new notes when they were introduced. For a financial institution to accept any sort of cash, they have various systems and security layers that need to be adapted to accept any new currency else it defeats the purpose of having sort of fraud detection service.
I know for a fact that in many cases banks have to rely on suppliers to modify equipment for them as many manufacturers ensure that the control over note recognition and detection stays with them. The reason for this is that the fewer the number of people who have access to a currency detection system's firmware, the easier it is to control.
It would be interesting to see if Gulf News manages to speak to the Central Bank as well as some of the commercial banks in the UAE and ask them how much notice and time they gave banks before introducing the new currency. Six months is a long time to wait but from what I know, the blame doesn't fall squarely on shoulders of the banks.