Domino-generated javascript fails

We’ve got web pages which contain horizontal image sets. Domino automatically generates a javascript function called dominoWellLoad to perform the mouseover effect. For some of our customers, our site has not been behaving properly. In attempting to duplicate the problem, we’ve noticed that some configurations complain about the dominoWellLoad function claiming that a variable is undefined. Unfortunately, we’ve been unable to find the common thread in these setups to determine where the problem lies. Any ideas? Ever run into this? TIA.