Two chords and a miss were recorded for this even using video OSD technique.

View the updated prediction.

Observers:
  1(M) D Gault,Hawkesbury Heights,NSW,AU
  2    S RUSSELL,Oatlands NSW
  3    H Pavlov,Braemar,NSW,AU
  4(P) Prediction, Sept 16

    

Discussion:

The ellipse above is plotted at the the same area as the expected 146km Diameter of Dione. With only two chord and a miss we can be confident that the path was close to that predicted for the event.

The figure below shows Hristo's light curve of the occultation.

Dave Gault also had a short dip in his light curve

but it was about 3 seconds too late to make a sensible fit to the other two chords.
On review I think his dip is a cloud or similar interference artefact and that he in fact had a miss for the following reasons:
1. The Object and Reference plots for Dave's data show a nice dip in both traces at the same time.

2. The 3 second offset would mean an unlikely (but not impossible) shape for an object of this size.

I have checked the CdR&CdL and DAMIT shape databases and Dione does not seem to have any useful entries for shape.
However the light curve in MPC Bulletin 32 (2005) on page 50 does suggest a lumpy profile.

Observational Data:

Observation details for MP (106) Dione
By Star              TYC 5831-00051-1
On 2009-09-26  at 16:42:33.0
_______________________________

Observer   Stephen RUSSELL
Location   Oatlands NSW
Longitude  +151:00:56.1
Latitude   -33:47:49.3
Altitude   60 m
Datum      WGS84
Telescope Newtonian
Aperture   20 cm
Seeing     Strong flickering Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  16:42:23.95
Reappearance   16:42:28.33
Comments:   Report prepopulated by OccultWatcher's Reporting Addin ver.1.1
_______________________________

Observer   Dave Gault
Location   Hawkesbury Heights,NSW,AU
Longitude  +150:38:28.
Latitude   -33:39:52.
Altitude   286 m
Datum      WGS84
Telescope Newtonian
Aperture   25 cm
Seeing     Strong flickering Clear
Timing     GPS - time inserted Video with frame analysis
Disappearance  16:42:29.46 (decided these are cloud or similar noise - see above - jt)
Reappearance   16:42:31.62
Comments: VERY jumpy sequence due to the wind, but good light curve....
I think! Light curve attached.
Report prepopulated by OccultWatcher's Reporting Addin ver.1.1
_______________________________

Observer   Hristo Pavlov
Location   Braemar,NSW,AU
Longitude  +150:28:56.4
Latitude   -34:25:49.7
Altitude   615 m
Datum      WGS84
Telescope SCT including Cass and Mak
Aperture   20 cm
Seeing     Steady Broken cloud
Timing     GPS - time inserted Video with frame analysis
Disappearance  16:42:27.36
Reappearance   16:42:40.40
Comments:   Report prepopulated by OccultWatcher's Reporting Addin ver.1.3