Many thanks I'll give that a try. I have had other cases of XP machines suddenly only printing blank pages on direct print HP printers (not networked ones), from MS Office applications, due to patch/driver version issues so that could well be the case here.
UPDATE :Renewal of printer drivers has no effect. Have also identified that Edit/Select All and Edit/Find do not operate other than as CTL A or F thus must be an IE7 config issue.