can not find prelude module

I originally used Redhat9.0, and the compilation is fine. But now I switched to Fedora 5, the compiler said it can not find prelude module! I used Yum to install the ghc-6.4.2, and it is put to into /usr/lib/ghc-6.4.2. I tried to add the directory to the makefile as : GHC_OPTS = -O2 -prof -auto-all -i../src:/usr/lib/ghc-6.4.2/ I also tried GHC_OPTS = -O2 -prof -auto-all -i../src:/usr/lib/ghc-6.4.2/imports but they didn't work. I am quite confused, isn't it that the base library(like prelude module) should be included in the search path by default? How can I deal with the problem? Thanks! TOm --------------------------------- Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail Beta.