First, service level SI10817 is way out of date. IIRC, that was the initial level when the product went GA. The last level was SI30707 from <a href=”http://www-03.ibm.com/systems/i/software/access/windows/casp.html”>just over two years ago</a>. That should be taken care of before anything else is even looked at.
Next, are any messages appearing in QSYSOPR related to iSeries Access? Your OS level is shown as V5R4 while iSeries Access is V5R3. Has there been a recent OS upgrade? You might need to attend to licensing.