awk in Fedora Core 3

[Enrico Vrgilli]

Hello, 

My problem is very simple, I hope... 

I have a file like this:

1.4  4.3   
1.3  4.2  
1.7  4.4
1.8  4.2  
1.1  4.5 
1.3  4.2  
1.6  4.4
1.5  4.1

I know that if I want a third column with the sum of this ones, 
I must write:

awk '{print $1+$2}' filename 

But the results is: 

5
5
5
5
5
5
5
5

But I want all the decimal number!!!! 

I have worked several times with Red Hat and I haven't had problem; 
now, with Fedora 3 I don't understand this result. 

Where is the problem? Is a bug of awk in fedora 3?
    
Thanks and Regards,

ENRICO VIRGILLI.