Publish method failing, can't understand why

[Mark]

(Excel 2002)
Have a button on a sheet2, which fires following code:

ActiveWorkbook.PublishObjects.Add( _
SourceType:=xlSourceChart, _
Filename:="C:\tempHold\test.htm", _
Sheet:="Chart1", _
Source:="", _
HtmlType:=xlHtmlStatic).Publish

Getting error 1004: method publish of publishobjects failed

I can't figure out why. What could I be missing???