IMO, the key is to make sure that the trailing garbage is included in the link:
Like this:
PHP Code:
http://www.sponsor.com/freesites/hfs#1/?nats=Chop:FU:CK
Not this
PHP Code:
http://www.sponsor.com/freesites/hfs#1/?nats=Chop
In February, a batch of Jayman Cash's hfs' got in the hfslink db with out the tracking stuff. Those are the ones that Fonz mentioned above and I corrected.
Also, I have noticed the use of commas in the linking codes with a NATS user like:
PHP Code:
http://www.sponsor.com/freesites/hfs#1/?nats=Chop,0,0,0
Depending on how your script is mass importing you should pay close attention to these.