Initially there was data on the disc and Ubuntu recognized it. I then blanked the disc(right click then Blank disc) and now Ubuntu does not recognize it anymore. :(
How can I resolve this?
You are probably using 10.04,wich has a bug in UDEV.Upgrade to Maverick (10.10)
If Ubuntu can not see your dvd drive any more, then it's more than likely a hardware fault. If it is I don't think there is any fix other than either taking it to a computer repair person or getting your hands dirty making sure everything is ok yourself.
To test it, boot from an Ubuntu Live CD, if that works, then Ubuntu is to blame. Please post in your original question more details about your problem. Make/model of dvd drive, do commercial disks work at all, what happens when you put a disk in, do you hear anything, etc.
Applications > Sound & Video > Brasero Disc Burner
thenTools > Blank
)?