Cubase plays back small clip of wrong section when I hit pla

Using xp pro 32bit sp2. I just upgraded to Cubase 5.5, but I was having this trouble a few days before the upgrade. When I’m in the middle of a song and I hit play after I haven’t hit play for at least a few seconds, it will just barely play about half a second of audio from somewhere else in the song. What in the world is going on? Why would it do this? It’s horribly annoying and makes it really hard to work.

Sometimes a delay plugin can cause this?