The kernel you flashed is too old for latest OS2008. You missed version info listed on my site but still sorry for that, it is too easy to miss it. I am not using pptp myself so I am quite slow in updating that kernel image. I'l try to do it tomorrow (~24 hours from now). I wanted to compile custom kernel for latest OS update for usage with my own device anyway so let's kill two birds with two stones at the same time ;-)