Thunderbird problem in Edgy

[Paul Thompson]

Hi,

I have just install Edgy on my Dell Inspiron 9100. All is working
well, even the Broadcom wireless card is detected. However Thunderbird
is a problem. I have kept my old profile (in fact my whole /home
partition from Dapper) and I am getting this message when I try to run
Thunderbird

"Mossilla Thunderbird is already running but is not responding.  To
open a new window, you must first close the existing mossila
thunderbird process or open a restart your system"

No other Thunderbird instance is running and restarting does not help.
Any suggestions as to what I should do?

Regards,

Paul Thompson