Jagged edges around inserted jpeg images

Hi There

I am using Adobe Acrobat Professional 8 in Windows 7 Professional 64 bit

When producing pdf's using Adobe Acrobat Pro 8 with the setting on high quality the images produced have very jagged edges (Jaggies) especially around logo's & imported images, not so much on text.

This has also been reflected in material that has come back from an external print job.

I had this problem on my olf pc & believe the fix for this was located somewhere in the advanced section of properties menu but i have not been able to find it.

Any help or suggestions would be greatly appreciated. 

Thanks

Darren