Their checks are sometimes late, have you tried contacting your affiliate manager? I always see mines online.
I worked with VINTACORE for couple of months They didnt made me payment for the leads i generated in August, September and October 2009 I send them emails they dont reply I did tried to contact them through AIM no answers and no one come online I did tried to call them like 10 to 15 times a day no one picks up calls goes on answering machine. Left message no one calls back even. Did searched there DOMAIN WHOIS for alternative phone number but on WHOIS also its the same phone number which they have listed on there website and no one answers calls there. Now i am planning to file complaints to Internet Fraud Bureau, Better Business Bureau and Other places