Hi, when I compile the kernel of N900(2.6.28-omap1) for the first time in scratchbox, the time is quite long, everyone knows that. And then I made some change of the kernel, recompile it, now the compile time becomes short.

But if I quit scratchbox and re-login it again, and re-compile the kernel, the time is as long as the first time I do it. Does anyone know why? And how to solve this problem?
Thanks!