Sounds like you're likely encountering an AOLserver Oracle driver bug,
but version 2.6 of the driver is truly ancient. I suggest trying the
latest Oracle driver from
SourceForge CVS.
If that doesn't fix the problem, you should probably submit a bug
report on SourceForge. If it
does fix the problem, you
should probably bug the AOLserver maintainers to release a more recent
version of the Oracle driver as a tarball for download.