This is a common concern, no matter how valuable or effective you might have been while working in the office. As a society, we are accustomed to associating "work" with "the office" and relaxation with being at home - so the natural tendency is to somehow assume that telecommuters aren't really working at home.

You have several options. First, make sure that your co-workers are aware of what you're producing. Don't take too much credit for your work or otherwise act like a superstar, but make sure your work doesn't become invisible. Your manager might be able to help you stay in the limelight in this respect.

Second, be sure you use the phone, e-mail, fax, and whatever other methods available to stay in touch with your co-workers while you're away. In the absence of some ongoing communication, they might assume that you're just goofing off.

Third, consider inviting one or more co-workers to visit you in your home office. When they see that you aren't lounging on the sofa or working in the hot tub (you aren't - are you?), and they see that you actually have a functioning office at home, they'll probably start acting differently. Keep in mind that any visits to your home must be at YOUR option, and only if YOU are comfortable with this.