New VB user needing HELP!... .

Using VB5 to control Word, which I am using as an HTML editor. Opening Word once using CreateObject, then opening numerous existing documents [.htm 's] (one after the other). Each document is opened as follows:
Set MyDoc = ObjWordApp.documents.open FileName:="C:\MyFile"

On each document I: find & replace, Save changes, and set all object variables to nothing (except the Word Application Object, which I set to nothing at the very end of looping through all the documents).

Works fine for 30/50 documents, but repeatedly crashes on larger numbers. What could I be doing wrong? Memory is the issue, but I release all object variables..... I make considerable use of find and replace - could this somehow be consuming memory?...

HELP!