Aaaahh...so you open up the location map where the text is encountered, record the event number for that map, then go to location events and type that in for 'packet number' and you can access the dialogue you want. Thanks for the heads up, now I can edit that particular set of strings with either of them.
There is no reason you should want an older copy of Temporal Flux. Especially not one so old that the dialogue text is still in the string editor. All features in later versions are additive improvements. None have been removed, though they may be in different places. Also, older Fluxes are not forward compatible with newer ones. Once you have edited a piece of dialogue with the newer edition, the older one will have no idea where it is (and may even crash).
With regard to the actual editing, you do not need to get the packet number separately, unless you want it for future use. When you find the location in question, click on the blue Event label. It will open up the associated event. All blue labels work in a similar manner.