Some people roaming in the EU on a Guido membership have reported that data did not work. In many cases the solution was to check the internet/APN settings and if the APN field has changed from 48months.liffeytelecom.com then edit it to change it back to that, save the changes and reboot and then see if data starts working.
BTW if you had internet access in the hotel then that was presumably via wifi and not 3G/data? Some people confuse the two but they are completely different ways to connect to the internet.
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.