0005393: Kernel 2.6.32-220 i386 "blocks" TFTP-Filetransfers

I have a CentOS6.1 box which serves as TFTP-Server for some routers. On these routers I usually copy the configuration via TFTP to this box ("copy running <a href="tftp://x.x.x.x/filename"">tftp://x.x.x.x/filename"</a> [<a href="tftp://x.x.x.x/filename"" target="_blank">^</a>]).<br /> After upgrading to CentOS6.2 with kernel 2.6.32-220 (or 2.6.32-220.2) I was no longer able to execute this operation as the Router timed out with the TFTP-operation. After rebooting with 2.6.23-131.21 the TFTP-operation works again.