Also, why are you still running Oracle 8.1.6.3 on your server? Is
some dependency preventing you from upgrading? I know 8.1.7.4 fixed a
long list of misc. bugs in 8.1.7.0, so presumably 8.1.6.3 had even
more bugs to fix.
Also, I don't whether or not there are any potential incompatability
issues between 8.1.6 and 8.1.7 versions of the client vs. server
libraries, like you're using. If you haven't already you should
probably look into that. But without knowing more, I'd assume that
just upgrading everything to 8.1.7.4 would be a good idea.
(Then finally upgrade to 9.x along with the rest of us sometime later,
of course...)