or adware in general?
If Ad-Aware then it should do. It scans your drives which includes all the folders on them, unless you have set it only to scan specified parts of your drive.
Opera has it's own pop-up blocker and cookie rule options doesn't it?
If so and if these are set to high security, perhaps you are just fortunate that you never have any malware.
Does AdAware check Opera too? The program never finds anything in the Opera cache.