Adam, Thanks for the reply.
I am already using an async load of the document using document load. The trouble starts once I try to process the document before displaying it. (Axel recently posted an XSL script which is doing a similar thing that I am doing in JS). The document load takes about 3 seconds the document processing takes just over a minute. Unfortunately I can't tack my processing onto the same thread as the document load. So that the callback only occurs when the deed is done. The alternative is to use XPCOM magic to create a thread and proxies to communicate progress back to the UI thread.
