Question: I have a Macbook Pro with Snow Leopard OS X. I use it's bootcamp utility to install Windows-XP and it has worked fine for me until one day I eject boot camp from my desktop. After that, when I want to reboot from bootcamp, it does not recognize that Windows is installed on my laptop!!!

Answer: 
Have you tried holding the meta/alt key during startup? This should show you a list of all available partitions and devices.
I understand that this happen because a third-party software (NTFS-3g)

It's a known bug (for quite some time, now). When installed, you can no longer have the Windows partition in the Startup Disk prefpane.

[special Tanx to @Loïc Wolff](https://apple.stackexchange.com/questions/419/what-are-some-of-your-best-itunes-add-ins)