Charge the correct rate for calls to land lines
Skype advertises a cost of €0.03 per minute to call land lines in Ireland. However, it is faulty, and can mis-identify land line numbers as premium rate numbers.
E.g. land line number: +353 (0)1 5141234
Skype will mis-identify this as a premium-rate number that starts with the "1514" prefix, and charge a rate of €0.34 per minute. Despite premium rate numbers not being contactable from outside the country.
I would suggest fixing number identification in Skype so it charges the prices advertised. The above Skype bug has costed me all my credit.