Leaking grey water tank

Hello,
On my last outing I had the following problem with the grey water tank on my 2004, 2720SL TM. Apparently I did not realize that it was getting full and it started to overflow. I have read on the TM forum that it would back up into the shower tub (which I was monitoring) if not emptied appropriately, but his did not happen in my case. What happened was the water started to leak out of the area underneath the TM where the top of the grey water tank meets the bottom of the TM. I don't think this is normal so I am asking if anyone has had this happen to them and how you handled it (which might remedy the situation for me). I have not tried to "debug" this problem at all since my trailer is in storage now. Just thought I would get some ideas, in advance, from this knowledgable forum. I have sent a note to the TM tech center asking their opinion but have not received a reply yet. I will post the reply when I receive it.
Thanks in advance for your input,
George