Lion Boot freezes on rotating backslash

Hello,

I am trying to figure out why my Lion install does not want to boot with my second hard (only used for storage) plugged in. It goes to the rotating backslash (/) and then freezes. Once I unplug the second hard drive it boots fine without any issues.

What could be causing this?

Thanks in advance

I started having this issue on Mountain Lion 10.8.4 . Did you ever find a solution?