Garmin GPS38 - last software update?

I've just obtained my first GPS receiver (and in case you're wondering, GBP 50, including the data/power lead), and was wondering if anyone knows what the last version of software update for it was?

I've searched the Garmin website, but all it says is that the model was discontinued (and thus no longer suported, which I expected, given that it's a single channel unit) in 2000. The software version in my unit is 3.07, by the way.

Thanks in advance!