You need save as a Pspimage or png.
If your image has 2 or more layers you save as pspimage.
so the layers stay unmerged.
You save as.png to keep your transparent background
if you have just a pic with no layers
You go file import as png wizard.
Make sure you check the keep transparent bacground box
when you save as .png.
Jpg doesnot support transparent backgrounds
or layers
which is why you are getting the merged layers message
and losing your transparent background.
Edited 8/27/2009 10:46 pm ET by gpamelac