DHTML issue operations break focus on first field in forms

As described in the comment:
http://confluence.atlassian.com/display/JIRA/Feedback+for+DHTML-loading+of+Issue+screens?focusedCommentId=38797319#comment-38797319

Insert-Focus is not on first field in screen.

When I "Log Work done" to an Issue:

without DHTML-loading the Focus is in the Field " Time Spent:"

with DHTML-loading turned on, the Focus is "nowhere" (most outer frame)