What model of router are you planning on using it in?
I was helping someone with a VWIC-2MFT-T1 today in a 1751 trying to do data (channel-groups) on it and they had one port working but were getting a tdm clock error and resource error when trying to configure channel-group on the 2nd T1 interface. I found a Cisco doc (don't have link handy) that said the VWIC in the 1751 only does voice applications with the IOS they had. And only one channel-group is supported but that was dependent on IOS version I believe. There was another doc that said the same card when used with a 2600/3600 could do data.
I would go to cisco.com and plug in the model of router and VWIC # and search and look at a couple documents. If you aren't able to locate the info there then call pre-sales # or TAC. Sometimes it is difficult to track down all the gotcha's. Let us know what you find out...
