Here is the Makefile.PL output with Perl 5.8 but the same unsatisfiing results:
C:\TEMP\DBD-DB2-1.79>perl Makefile.PL
Configuring DBD::DB2...
Remember to actually read the README and CAVEATS files!
Using DB2 in "C:/PROGRA~1/IBM/SQLLIB"
System: perl5.008008 DBI1.609 MSWin32-x86-multi-thread dl_win32.xs
Compiler: cl -MD -Zi -DNDEBUG -O1 -nologo -GF -W3 -MD -Zi -DNDEBUG -O1
+ -DWIN32 -D_CONSOLE -DNO_STRICT -DHAVE_DES_FCRYPT -DNO_HASH_SEED -DUS
+E_SITECUSTOMIZE -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PER
+LIO -DPERL_MSVCRT_READFIX
Includes: -I"C:/PROGRA~1/IBM/SQLLIB/include" -I"C:\Perl\site\lib/auto
+/DBI" -I"C:\Perl\lib/auto/DBI" -I"C:\Perl\site\lib/auto/DBI"
Libraries: -L"C:/PROGRA~1/IBM/SQLLIB/lib" db2cli.lib db2api.lib -L"C:/
+Programme/Microsoft Visual Studio 8/VC/LIB" -L"C:/Programme/Microsoft
+ Visual Studio 8/VC/PlatformSDK/lib" -L"C:/Programme/Microsoft Visual
+ Studio 8/SDK/v2.0/lib" -L"R:/Online-Entwicklung/SW-Architektur/Laufw
+erk-i/C_LBSDB5/libnt"
Checking if your kit is complete...
Looks good
Checking if your kit is complete...
Looks good
Writing Makefile for DBD::DB2::Constants
Writing Makefile for DBD::DB2
C:\TEMP\DBD-DB2-1.79>
That looks fine for me, all paths are correct and the DB2 libs and incs are found.
And it came to pass that in time the Great God Om spake unto Brutha, the Chosen One: "Psst!"
(Terry Pratchett, Small Gods)