I have noticed that when I start up my laptop, it shows GRUB like usual but then it black screens for about 5 seconds, displays a message about support for core revisions 0X15 and 0X17 being disabled, and then displays the startup splash screen. What is Ubuntu doing during that black screen?
Create a file
/etc/modprobe.d/local-b43.conf containing the line
options b43 allhwsupport=1
Then, run the following commands
sudo rmmod b43
sudo modprobe b43
I think you are using a Broadcom (BCMxxxx) wireless card. The message is telling you to pass an option to the b43 kernel module to activate support for your wireless driver.