Reference page: Error, Bug, Issue, Incident 

The notable comment about word “issue” used in software testing context is that it’s often referred as a problem or an obstacle – which is uncommon meaning.  Generally, an issue is defined as “something that is sent out or put forth in any form” (Dictionary.com).

Wikipedia explains this discrepancy with the following.

In computing, the term issue is a unit of work to accomplish an improvement in a system. An issue could be a bug, a requested feature, task, missing documentation, and so forth. The word “issue” is popularly misused in lieu of “problem.”  This usage is probably related.

For example, OpenOffice.org used to call their modified version of BugZilla IssueZilla. As of August 2006, they call their system Issue Tracker.

Indeed, I more often heard “issue” from project managers and business analysts than from fellow testers and programmers.