Web Master:
Hi John
Unfortunately, your photos were not attached, but I think that the problem may be caused by root rot.
It is very tempting to move a plant into a much larger pot but this is not always a good idea. The ratio of soil to root area increases that also means that the amount of soil and therefore water around the roots increases and can lead to root rot.
The general rule when moving a plant to a larger pot, the increase in size should be 5-10cm. The rule doesn't apply for plants being planted directly into the soil because water drains through the soil and is not left around the roots.