Junk E-mail list error

Hi,

I am getting an error on some of my exchange users accounts. "An error occured processing you Junk E-mail lists. You are over the size limit allowed on the server. Contact your server admin." I have increased the size for the number of Junk mail entries and other settings using the OWA admin tool. All of the answers i have seen at other sites recommended this. Any other suggestions will be appreciated.