Worker process not releasing memory and Oracle connection not closing

Worker process not releasing memory and Oracle connection not closing

I have an issue where my .NET 3.5 applications are causing the IIS worker
process to continually eat up memory and never release it until the
applications start throwing memory related errors and I have to recycle
the IIS worker process. Another thing I've noticed is that the connection
to the Oracle DB server also doesn't close and will remain open until I
recycle the IIS worker process (as far as I can tell I'm closing the
Oracle connections properly). From what I've read in other similar posts
the GC is supposed to clean up unused memory and allow it to be
reallocated but this is quite clearly not happening here (I'm observing
the same problem on both the remote host and local host. I'm going to
assume that this isn't an issue related to IIS settings but rather that
I'm not doing proper housecleaning in my code; what things should I be
look at? Thanks.