What membership do you have? EU roaming only works on Guido. Do calls and texts work? If they do and data doesn't then check your internet settings and if the APN field of your settings has changed from 48months.liffeytelecom.com then edit it, change it back to that, save the settings, reboot and see if data starts working. This is a common problem for users who are roaming on the EU on a Guido membership but data does not work straight off.
Hope this helps.
I am not a 48 employee so if you need to contact 48 support then use option 3 or the chat facility here.