Please show what's in the file.
Is there a white rectangle shape behind the 6 dots that defines the boundary of the image in the Ai file?
If not, then only the grey dots would be exported with a transparent background.
Below is a screenshot of a AI file exported as PNG and viewed in Photoshop.
The boundary of the exported image is defined by the outermost elements. So I suspect in your case, there is a white opaque rectangle which is the reason why you didn't get a transparent backgound.
I don't have Illustrator CS5 so I used CS3. Hope this helps.
The rectangle shape is the same scale as the image that it will overlay.
This puts the needle rotational axis (dots), for each gauge in the proper
place. It is intended to simply be a layer on top of the gauge needles and
dials. I'll try to export using the boundary of the image itself. Thanks!
I usually export AI to PSD first then saves to other formats in Photoshop. There you can increase the boundary and do other adjstments/touchups before saving it in PNG or JPEG as needed.
please, show the same image from your post #2 again after you choose View > Show Transparency Grid
Sorry for the late response but I got it thanks to yur help!