Taped MPEG footage imports on CS 5.5, but not on CS 6????

I have both Premiere Pro CS 5.5 and CS 6 installed on my computer.

I have been given footage that was shot on a DSLR and 1 was shot with a Tape.

I imported the DSLR Footage, whch is MPEG 4 Format, in CS 6 without a problem.

I went to import the Taped footge, which is MPEG format, and it did nit import into CS 6. I get the following POP UP Box:

When I Open up CS 5.5 and I import the DSLR Footage, It works Fine

When I Open up and Import the same Taped Footage in CS 5.5 It works great as well. It imports perfectly.

Why would it work on CS 5.5 and not on CS 6?

P.S. The taped footage was captured using CS 5.5