Hello. I updated my Ubuntu, and after that there were two new lines on my GRUB screen.

Ubuntu 9.04, kernel 2.6.28-16-generic
Ubuntu 9.04, kernel 2.6.28-16-generic (recovery mode)
Ubuntu 9.04, kernel 2.6.28-11-generic
Ubuntu 9.04, kernel 2.6.28-11-generic (recovey mode)
Ubuntu 9.04, memtest86+
Other operating systems:
Microsoft Windows XP Home Edition

Do I have two kernels installed?
Do the old entries are still useful?
Each kernel takes up space? :P

And that's not all, when a get into the old version of Ubuntu, the wireless card stops working on any Ubuntu version until I get into Windows and then go back to Ubuntu.

Thanks for your help.