oddity with package prefixes for data constructors

consider

$ ./ghc-6.9.20080514/bin/ghcii.sh
GHCi, version 6.9.20080514: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ... linking ... done.
Loading package base ... linking ... done.
Prelude> :browse Data.Time.Clock
getCurrentTime :: IO UTCTime
newtype DiffTime
  = time-1.1.2.0:Data.Time.Clock.Scale.MkDiffTime Data.Fixed.Pico
newtype NominalDiffTime
  = time-1.1.2.0:Data.Time.Clock.UTC.MkNominalDiffTime Data.Fixed.Pico
data UTCTime
  = UTCTime {utctDay :: time-1.1.2.0:Data.Time.Calendar.Days.Day,
             utctDayTime :: DiffTime}
newtype UniversalTime
  = ModJulianDate {getModJulianDate :: Rational}
addUTCTime :: NominalDiffTime -> UTCTime -> UTCTime
diffUTCTime :: UTCTime -> UTCTime -> NominalDiffTime
picosecondsToDiffTime :: Integer -> DiffTime
secondsToDiffTime :: Integer -> DiffTime

there is only one time package installed, so i'm surprised to see any package prefixes at all here

$ ./ghc-6.9.20080514/bin/ghc-pkg.exe find-module Data.Time.\*
c:/fptools/ghc/ghc-6.9.20080514\package.conf:
    time-1.1.2.0

but by what system do some things get prefixes and others don't? are there any invisible modules that need the distinction, or is this an output bug?

Trac metadata

Trac field	Value
Version	6.9
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	GHCi
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Unknown
Architecture	Unknown