Bender Should Not Be Allowed on TV - S5-E15
Corrected entry: Whenever the Network Execubot is talking it appears in a box with a scroll bar like it was just a file playing. Naturally if it were actually talking this would not happen. I think it must be a deliberate mistake, making fun of this sort of error that often happens in films (there is a good example of this in Jurassic Park), as it's ridiculous that they would have animated this and not realised the error.
Correction: This is a gag, not a goof, EXACTLY as you noted. There is no goof.