Hi G,
I've been suffering from the same problem more than one year with my
156/2.0 JTS 2005.
Luckily my dealer was very kind and serious about this problem. Every
time I brought my car they changed brake/clutch fluid and even clutch
master cyclinder twice, though the problem still persisted. It was ok
for a while, say 3000km after the service, but it will almost always
recur.
Eventually they did the right thing (which I can't remember) at the
last service and I haven't seen the problem recur more than 10,000km.
I think the problem is gone.
I'll check with my garage what they have done and get back to you.
rin
Saitama, Japan