RAS into a Brooktrout IRAS board

I have set up a Brooktrout IRAS24-AC RAS board into a NT server. I am able to get a W95 computer to dial in, validate and run the script file. I have not been able to do the same on a W98 or a W2000 computer. Both the W98 and W2000 computer gets logged in okay but will never validate or run the script file. It seems to me that it is a timing issue, therefore getting a timeout before it makes the connection to the domain controller. Has anyone experienced this situation. If so, were you able to correct it and how? Brooktrout has made a statement they will not support W2000, however I am assumming that is for a W2000 server. Any help would be appreciated.