Neighbour table overflow with 2.2.19 kernel

Hello, I'm using SuSE 7.3 with the 2.4.10 kernel on my firewall/router, but when I try to install the 2.2.19 kernel instead I get Neighbour table overflow errors all time time and errors that NET: has surpressed 'between 500 and 3000' messages. And my internet connection (through PPTP) doesn't work anymore. Is it possible to get around the errors with the 2.2.19 kernel? Thanks in advance.