I need some advice from you expert members.
I just been advised by Air Canada that there is a schedule change for my LH738 flight. The 'safe enough' original 80 minutes connection is reduced to 40 minutes at HKG. I know that this connection time is below the recommended minimum connection time for HKG, but is it possible to connect in 40 minutes at HKG between these two airlines?

This is what stated on my AC reservation:

LH738* Frankfurt, Frankfurt Int'l (FRA)
Fri 16-Dec 2011
17:35 - Terminal 1
Hong Kong (HKG)
Sat 17-Dec 2011
11:10 - Terminal 1
First Class

Airport change from Hong Kong (HKG) to Frankfurt (FRA).

LH738* Frankfurt, Frankfurt Int'l (FRA)
Fri 16-Dec 2011
18:00 - Terminal 1
Hong Kong (HKG)
Sat 17-Dec 2011
11:50 - Terminal 1
First Class

SQ891* Hong Kong (HKG)
Sat 17-Dec 2011
12:30 - Terminal 1
Singapore, Changi (SIN)
Sat 17-Dec 2011
16:20
Business Class

Yet, another problem:
I have another connecting flight to CGK on the 17-Dec with the unchangeble revenue LH790 flight depart SIN at 18:00.

There are no other alternate F award availability that I can currently see, which will connect me to my LH790 on time.

Can anyone give me a light in regards to the trouble possibility for this 40 minutes connecting time?

Thank you.