help with new dracaena -

I have several dracaena through out the house and all have done well with the exception of the newest guy. I bought this Dragon Tree at Home Depot three weeks ago - and since then, the base of the leaves have started to yellow and the leaves drop off. Some of the tips were already scorched - but it didn't have this problem when I bought it.

What is it? Not enough light? To much water? I haven't found any webs, but could it be spider mites?
Attached are some pics. Thanks for your help -

Whole Plant:

closeup:

pic of one of the dropped leaves. There were about 10 today and it seems to be coming off of two of the stalks in particular (smaller ones)"

how they look on the stalk:

anybody have any ideas....I don't want to lose this guy

If you squeeze the stem/trunk near where the leaves are falling off, does it feel solid or squishy? I lost a dracaena I think from overwatering, the symptoms first started just like you're describing with leaves yellowing and dropping off, and as time went on the stems felt squishy too. I wasn't able to save mine, but if you caught yours early then there's still hope. My guess would be that the people at Walmart didn't water it appropriately, I'm sure it's not your watering because you have others that are doing fine. The tips looking scorched is probably just from low humidity and I wouldn't worry about it too much.

As far as saving it, if it is overwatering/root rot, I would repot in fresh soil and rinse the roots with some diluted hydrogen peroxide before you put it in the new pot. If you don't want to repot, you could try just watering with peroxide, that's supposed to "cure" overwatering too.

thank you so much - I had never heard of the hydrogen peroxide trick.

It may be stress of going from optium growing conditions (greenhouse) to drier, darker environs. If it is just leaf drop then I'd consider this normal. Cut back on watering if the soil is wet and give plenty of light and increase humidity until it levels out.

Mine loses a lot of leaves in winter and basically stops growing. It picks up growing the next year after I move it outdoors.