It's been a while since I've messed with cuebase but I'd suggest that you try what Excio said. If that doesn't work, check your export configurations and try again. It sounds to me like that sound might be coming from a send channel reverb and I've had trouble with reverb and other 3rd party plugins in the past with cusbase. So you may want to check all your reverbs, delays and automation settings also and try disabling a few until you find the culprit.