Campaign tracking not working - Please help!

[hpops]

I have recently installed campaign tracking for a client and can't get it working - I've checked it and checked it and can't see why it's not tracking. I have also checked that my ip is not being blocked so it's not that - could someone please have a look at the url and tell me if it looks ok?
http://www.example.com/productinfo/example.asp?utm_campaign=example_medium=banner

if the url is ok - what else could I look at?

many thanks

[edited by: engine at 8:24 am (utc) on Oct. 2, 2007]
[edit reason] examplified [/edit]

[bill]

Have you contacted the company running the campaign, or are you running this yourself? In other words, where is the URL not being tracked? On their end or your end?