I finally bought a Fine Offset/EasyWeather type of station, exactly this one:

The memory is already full so I installed the Easy Weather to backup the data in the computer and start recording again in the station memory.
Easy weather took all the data just by selecting the type of station and connecting USB cable, but I find the software a bit poor (specially the rain graphs, that only show the accumulated amount of rain instead of the rain-rate, so the graph will always be moving up no matter the amount of rain).
So I installed cumulus, selected Fine Offset in station type and it instantly connects to the station and shows the current temperature, etc.. but I can't upload the data from the station to cumulus.
What am I missing?