Is this a north American PS3, UK PS3, Japanese, etc.? How did you update to 2.0?
Going by what i am seeing on a Google search that error seems to stem from using a firmware update not made for the system it's installed on (using the North American file on a Japanese PS3 as an example). If this is the case running the system update from where your console originated should possibly fix things. You would have to download it on your computer and transfer over using a memory card or USB drive.