GHC-5.04.2 generates faulty Core code?

I am currently working on my master thesis which is designing and 
implementing an usage analysis for Core. I have been working with 
ghc-5.02 but want to start use ghc-5.04.2 instead. The problem is that 
it seems like ghc-5.04.2 generates faulty Core code.

I need to generate Core for the entire prelude and parts of the hslibs 
modules.

What I do is:

ghc -fno-implicit-prelude -fno-code -cpp -fext-core -fglasgow-exts Base.lhs


Then I try to analyse Base.hcr using my own program. I then get an error:

Base.hcr:1261:
Invalid variable name in getCoreType, (Just "GHCziBase","zeze")


This occurs since my program cannot find the type for GHCziBase.zeze 
which is refered to at line 1261 in Base.hcr.

If I look at that line in Base.hcr I find:

GHCziBase.zaza (GHCziBase.zeze @ a zddEq x y) (zeze5 xs ys)};


But there is no definition for GHCziBase.zeze in the file Base.hcr. It 
seems to me that GHC generates faulty Core code.

Am I doing something wrong? Should I try to use another version of GHC?


Thankful for help

Sincerely,
 Tobias