This is reported as not being true at the follwoing website

http://graphicssoft.about.com/library/weekly/aa0104jpegmyths.htm

"JPEGs lose quality every time they are opened and/or saved.
False. Simply opening or displaying a JPEG image does not harm the image in any way. Even opening an image and saving it again under a new name will not introduce further compression, unless additional editing was performed on the image. Saving a JPEG repeatedly during the same editing session (without ever closing the image) will not accumulate a loss in quality.

JPEGs lose quality every time they are opened, edited and saved.
True. If a JPEG image is opened, edited, and saved again it results in additional image degradation. It is very important to minimize the number of editing sessions between the initial and final version of a JPEG image. If you must perform editing functions in several sessions or in several different programs, you should use a image format that is not lossy (TIFF, BMP, PNG) for the intermediate editing sessions before saving the final version. Repeated saving within the same editing session does not introduce additional damage. It is only when the image is closed, re-opened, edited and saved again."