thunderbird woes

[the.phule]

G'day all,

Have just installed 4.3 and am trying to get thunderbird working with
my copied profile, i've followed the online help for copying a profile
but appear to have got thunderbird stuck thinking its constantly
started so i get

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

Problem is ps -aU username isn't showing a thunderbird process so i
cant kill it anyone got any ideas as to where it puts the lock on
starting etc?

Cheers

Kim