The Dial-in Conferencing Settings page in Office Communicator Web Access 2007 R2 prompts you to enter a PIN that is at least 5 digits even if the PIN length policy is set to use a PIN that is less than 5 digits
The PIN length policy is set to use a PIN that is less than 5 digits. However, you receive the following message on the Dial-in Conferencing Settings page in Microsoft Office Communicator Web Access 2007 R2:
Your PIN must be at least 5 digits and cannot include letters, spaces, sequential numbers, or special characters. You will use this PIN when dialing in to conferences and meetings on your company network.
To resolve this issue, apply the update that is described in the following Microsoft Knowledge Base (KB) article:
Description of the cumulative update package for Office Communications Server 2007 R2, Communicator Web Access: April 2010
After you apply the update, you receive the following message on the Dial-in Conferencing Settings page:
You will need a PIN to dial into meetings on your organization's network from an outside telephone. Your PIN can contain only numbers, and it must contain at least the minimum number of digits set by your administrator.