There is a difference in the versions for both the exp and imp utilities.
The general rule is to use the newer of the two tools...

i.e. Run the exp tool from the 8.1.7 to do the export and not from the 8.1.6
In the past I have had to install the older version in a new folder (Just Oracle Database Utilities...) In order to do this...

-The problem could also likely be that you are using personal edition.
I usually just install the normal Oracle 8i on my Laptop ...

Also are you sure the procedures are created by the user you have exported and not another???

The exp utility usually works just fine to move a schema I use it all the time.

But if you just need the stored procs try to recreate the procs into a text file with :

select NAME,TEXT FROM USER_SOURCE;

Somewhere I have the full script but can't find it right now...

It involves setting
spool on
then fetching user_source into a cursor and then doing a DBMS_OUTPUT.PUT_LINE() for each line.

However, When I import and export from enterprise edition to enterprise edition it works fine.

HTH