"Yahweh created me, first-fruits of his fashioning,
before the oldest of this works." - - - Proverbs 8:22 (New Jerusalem Bible)
For those with the dedication, eye for detail, and a voracious reading appetite, there is always something to be gleaned from the judicious textual notes provided in the fully annotated editions of the New Jerusalem Bible. For those with background in the ancient languages, there is enough material for you to go back and trace the logic behind a given decision.
In the passage cited above, the NJB follows the Septuagint in translating the Hebrew root. The root can be translated variously as "to possess/acquire", "to father/begat" or "to create." The LXX's reading (ektisen), to which the NJB looks to clarify the Hebrew text, seems justified based upon the history of the Greek text and parallel Semitic literature. One necessarily thinks of the verb bara as the principle example of verbs meaning "to create" in Biblical Hebrew.
The traditional Western translation (possessed) is attested since at least the production of the Vulgate. One would have to consult the Vetus Latina volumes to see if it goes back prior to the attempts to align Western translations with the Hebrew text.
So how valuable is the Septuagint's rendition of the text? It largely depends upon the scholar you consult or one's own reading of the Hebrew or the Greek. If one believes the LXX has a considerable claim to representing a different but equally authentic textual tradition for which the Hebrew originals have been lost, or if one sees the LXX as a reasonable cultural linguistic indicator of how Jews with knowledge of both Hebrew and Greek interpreted their texts, then leaning on the Septuagint is a justifiable decision. Admittedly, however, preference for the LXX reading of a given passage is often a seemingly esoteric exercise. While there are times the Hebrew text is so corrupt so as to leave little doubt one should consult the Septuagint, there are other times where the reasons for appealing to the Septuagint rest on an extremely fine argument, delicate in its construction and precise in its details.
This is mere speculation, but the significance of the LXX's reading may be very subtle and may throw some light into how the above passage was received in antiquity. Generally speaking, bara indicating a creating action of God that was entirely new, with no previous reference point. It is also one of the verbs in the Hebrew Bible used exclusively in relation to God. The Septuagint text may indicate that the use of the root in Proverbs provides a subtle clue that before creation of new things by God, Wisdom was already there, making her presence as either a creation event that is part of an unfathomable past or as indicating her co-eternal nature with God. Again, speculation, nothing more.
It should be noted that historical criticism sees the personification of Wisdom as a remnant of pre-Monotheistic religion. This is very much a matter or scholarly speculation; the bold face evidence appears somewhat more ambiguous. I could be very much mistaken, but it seems to me that we do not have a definitive account of Wisdom's role (as a personified figure) in pre-Christian Judaism. We know the figure features in certain literary works, notably the Wisdom of Solomon, and one could considerable work construction the narrative of Wisdom in these texts, perhaps going so far as to outline a tentative mythology. It remains to be seen how Wisdom, as a feminine figure, actually functioned in Jewish observance outside of a strict literary corpus.