Any text drag causes bar to show up

I can reproduce. Also, if you have your window positioned so that the launcher stays visible and drag some text to the left the launcher will momentarily hide and then come back.

same case here i also having this bug and can reproduce it

This seems to be a bug but please mention that if for instance you drag an image from i.e. firefox and the bar appear, and you drag the image inside the bar, then the system hangs for a second or two and then it makes invisible all the launcher icons except from GIMP and Firefox (2 known applications than can open images).

On the other hand, this isn't happening while dragging text (all the programs become invisible while dragging text above the bar, including gedit) and that's probably the actual bug!

This bug was fixed in the package unity - 4.8.2-0ubuntu3

---------------
unity (4.8.2-0ubuntu3) oneiric; urgency=low

  * Update to current trunk to get closer from an usable version, including
    - improvements to the alt-tab switcher, fixing the performances issues
      on intel cards, thanks Jason Smith
    - reworked dnd code fixing launcher showing when dragging text(lp: #773028)
      or widgets (lp: #724986), the expose slowness (lp: #821538) and other
      bugs as well, thanks Andrea Azzarone
    - the dash text is selected by default allow to type directly a new command
      (lp: #826904)
 -- Sebastien Bacher <email address hidden> Fri, 19 Aug 2011 18:04:19 +0200

Nice! Congrats!