[Adobe Illustrator CS3] Check Transparency before converting image to mesh object

Last night I made a mistake and turned an hour plus work into something not so useful.

Basically I try to put some real world clothing pattern on a texture mapping template I created on Adobe Illustrator CS3. Everything went well. But before I convert a texture (JPEG image) into mesh object so that I can wrap it on a texture mapping template, I changed the image's transparency BEFORE converting to mesh object. That's NO NO because after the convertion. The low transparency became 100%! That means I can never get back to the original transprency.

So next time I should remember to FIRST convert a bitmap into mesh object BEFORE I change the transparency value.