I get the same block of "error:null, null" in my startup (windows machine over here), and I have run the computer craft fix steps, which have actually fixed the errors with not being able to make computer blocks (even in a normal bench they craft correctly, no blinky-thing).
The block of errors still scares me a bit, but everything seems to be working fine, ignorance is bliss, I guess...
EDIT:
OK, well I took a look at the custom_recipes.txt in the RecipeManager folder in plugins, and the recipes in question all use item 177 with data codes ranging 0 thru 7, 10, 11, 13, and 15, all in unshaped recipes making a bunch of different stuff, some vanilla
A quick check in-game reveals nothing with this id, so I assume the code for it was changed in the update, so I'm just going to comment out the recipes for now. Anyone know what that item was beforehand?