Seen (and heard) at 123greetings.com:
Not only does the pictured advertisement flash and bounce, it DINGS, and it keeps on DINGING, sounding exactly like the Windows Error sound effect. The sound is so intrusive that my husband came in to my office from another room to ask me what was wrong with my computer! What a wonderful way to chase people away from a web site.
Just to make sure that an error on the web page was not triggering the Windows Error sound effect, I downloaded a copy of the SWF, and sure enough we find that it contains a sound file: