Using IE to open a web based Word doc.

When clicking on a link on a web page that is a linked to a Word document, It opens 2 blank (grey) instances of Word. (If you minimize them, the actual document does show up in IE). Why are these 2 blank Word windows popping up? It opens the filein IE fine from any other machine. Using IE-6, Windows 2000 Pro/ SP2, Office 2000/ SR1.