Opinions wanted....

I'm looking for opinions on what's reasonable expectations for support from
an ISV.

Here's the deal.  
We purchased software to perform a specific business function that is
necessary for the proper operation of our business.  This software is sold
as a "Software Development Kit", and is intended to be used by developers
within applications, either developed in-house, or purchased.  This SDK is
written in ILE C, and all documentation for this SDK is focused on that
specific language environment.

I converted the .h prototypes delivered with this SDK into RPG prototypes,
so that we can use this SDK within our RPG applications (V4R4).  So far, so
good... Everything seems to work reliably most of the time.  We deploy the
interface in a service program.

I recently changed my implementation of this SDK, ran the modified service
program on our development and testing box for nearly three months, without
any indications of failure.  Once we moved this new service program to
production, under real application loads, all h#!! broke loose.

Please note that I have since determined the cause of this issue, and have
corrected my error.  It was MY error, in that the original prototypes I
created in RPG had parameter sizing issues.  Barbara Morris' excellent
document "Converting from C prototypes to RPG prototypes" gave me the
answers I needed to correct the prototype issues.  Given the improved
support for C function calls since V5R1, we now seem to have stabilized
again.  It's interesting to note that we ran this SDK for two years using
the incorrect prototypes, without any significant issues.  Additionally, one
of the earliest applications I wrote to use this SDK was written from the
documentation code samples, which were using deprecated functions.  These
APIs had replacements that were recommended for use in lieu of the others.
The deprecated functions were still functional, just not recommended.

Here's the issue....
I called this vendor to get support on the runtime issues we were seeing
(before I found and corrected the prototypes).  This vendor provides support
for end-user issues, and installation issues, but does not offer support to
developers and the issues relating to the use of this SDK.  I'm a bit
alarmed by their lack of support to developers, since this product is sold
as an SDK, which implies that it is supposed to be use by developers.  I am
currently trying to determine if there is any way I can obtain the level of
support I need for the next time that I have issues like this.

Any opinions?  


Eric DeLong
Sally Beauty Company
MIS-Project Manager (BSG)
940-297-2863 or ext. 1863