AU3 XR8 almost stalling?

[b2tf]

Had a bit of a scary one in the ute this morning, jumped in and started it for the first tim of the day, put it into gear (auto) and the thing struggled to move and almost stalled, had to really plant my foot to get it to go.
The oustide temp wasnt cold but it didnt get down to -1 last night, would it just be temperature cuasing this or is there something I should check? It hasnt done it before, and once it up was up and going it had no problems at all.

Just want to be sure that there's nothing wrong with the machine!