International connection issues

[alistair.cane]

On Thursday evening last week (4 November), my other half was stuck at Rome airport. She tried to call me numerous times (her Vodafone to my O2 network) between 4.45 and 5.30pm GMT and either couldn't get through (although we both had a full signal) or got through to a completely wrong number - all of which was hugely distressing. Any ideas as to what could have caused these connection issues?

[Fonefixer]

How did she dial the number?

To call the UK she should use 0044 then the number omitting the first 0 from the code.

ie if my number is

07123 123456

she should dial

0044 7123 123456