Awk - Script assistance on identifying non matching fields

Hoping for some assistance.

my source file consists of:

os, ip, username
win7, 123.56.78, john
win7, 123.56.78, paul
win7, 10.1.1.1, john
win7, 10.2.2.3, joe

I've been trying to run a script that will only return ip and username where the IP address is the same and the username is different .

so for the example above my results should be:

win7, 123.56.78, john
win7, 123.56.78, paul

of course ip and username's will vary across the dataset.

I've used the script below to get the count of all unique IPs and username relations, but i need to take it a step further and I'm stumped.
any help is appreciated.

awk 'BEGIN { FS = "," } ; {count[$2 "," $3]++}END{for(j in count) print j ","  count[j]}' 

-TekVaio

Try:

awk -F, '++a[$2]==1{x=$0}a[$2]==2{print x;print}a[$2]>2' file

Thanks for your reply bartus11

However, it did not seem to deliver the results as it printed out many unnecessary fields . Below is what i used and it produced the results necessary.

Then the data you posted doesn't match the data you have, because it works absolutely fine here. Please post some of your actual data.