A recently installed toilet is giving us fits. It has been removed twice and re-installed to no avail. It makes an odd whistling/wheezing/hard-to-describe sound when it is flushed. Then several days later, we noticed that the second toilet in the other bathroom has a "wave" when the first toilet is flushed. (They are back to back on either side of the same wall.) Then realized that the whistling toilet also has a wave when the second toilet is flushed. This seems bad, very bad. The installed toilet is the same as the other 2 toilets in the house, and we haven't had any trouble with them. Any ideas or suggestions would be great appreciated! Thank you!