Well it has to be either of those two either hosting server issue or inputting wrong info that is causing the hosting server's php to go ballistic.
Is there any hints in the HOSTING error log that would assist us here? Selecting vb2 would not be correct unless you have vb2
I would suggest looking at your vb3 config file and ensure on the config and step 4 all the proper database info mysql prefix cookie prefix are entered and try again selecting vb3 and continue. Please then try getting any errors and post them here so we can assist.