I am facing the exactluy similar issue in R12 APEXP workflow.
In my case also approver has approved the workflow but it got stuck at block activity in the main workflow.
I tried to debug the issue and found that in the AME approval workflow ,a function AME Complete Approval is called after the approver has taken the action(reject or approve).
this function in turn calls the wf_engine.completeactivity API......the output of this API should act as the response to main workflow(block) and it should start moving but its not happening.
WF_ENGINE.CompleteActivity(itemtype => 'APEXP',itemkey => XITMKEYW ,activity => 'AME_APPROVAL_BLOCK',result => Null);
DBMS_OUTPUT.PUT_LINE('result is : '||result);
DBMS_OUTPUT.PUT_LINE('Error message : '||SQLERRM);
I tried to run the complete activity from outside also and to my suprise i could see time stamp getting changed for the block but it still didnt proceed.
i think this may be an oracle bug with R12. Please guide.
We are experiencing this same issue for 11i APEXP as well. We are only seeing it on occasional Expenses as well since the majority go through without a hitch. I have not opened an SR yet, but maybe I will since this appears to be a reported issue.