PostgreSQL help

Hey!!

I have a problem and i hope this is the correct section to post it!!!

When i use the COPY  Table Name FROM Location command to insert values to a 
table using a txt file, the programme gives me errors when he finds letter 
as "ò, è, à" inside the txt file.
But when i use the insert command and I write some word with any of the 
letters it seems to work. Why is that ?? What can i do to resolve it??

i use the programme PgAdmin 3 to write my commands...

Thank you.