Lion, and losing networked external disks

Two montha ago, my MacBookPro (running Leopard) died, and I bought a new MacBookPro running Lion.

Ever since I have had major problems with my external hard disks. Under leopard I only had to mount them once, after a restart; they would remain available no matter what. Lion however keeps 'losing' the external disks. Sometimes I can remount them, but often the only solution is to shut down and restart the disk, or (if even that won't work) to restart my computer. Needless to say that all the restarting of the external disks cause quite some wear and tear...

Under Leopard, the set-up worked as a charm and I never lost the connection to any of my external disks.

My set-up:

• The router takes care of the internet connection;
• An Airport Extreme ('Jaguar') is connected to the router, via an ethernet cable;
• The Airport Extreme controls my LAN (PowerBook, MacMini and iPad), and also connects to an Airport Express (plugged into my stereo).
• Four external disks are plugged into the Airport Extreme, thus making them available to the whole LAN: 1 external disk connected by ethernet, and 3 external disks via USB.

I connect to the external disks via Finder, using the 'Shared' header:

• Clicking on '$Ethernet-disk SMB' connects me to the Ethernet external hard disk;
• Clicking on 'Jaguar' shows the three external disks connected by USB, which I can then mount one by one.

Under Leopard, all these connections / mounts were treated as stable. Under Lion however, they are not. Lion seems to renogiate the connections all the time, and often can't maintain them once they've been established.

The problem might be how Lion manages its own connection to my Airport Extreme ('Jaguar'). After the connection to an external hard disk is lost, I try to reconnect in Finder via Jaguar (either in the shared section, or by going to 'Network' in Finder). More often than not, Finder will ahow that my MacBookPro is attempting to connect *anew* to my Airport Extreme - even though it is actually already connected to it, as is proven by the fact that my MacBook can actually access the internet at that time.

So it boils down to Lion losing its connection to the *disks* mounted via Airport Express, while having a working connection to that same Airport Express.

I'm getting quite fed up. Under Leopard, the connection with my networked disks was completely stable. Under Lion, my computer loses its connection to them a number of times *per day*, which is ******* up my access and all my back-up scripts. I'd be quite relieved if somebody can come up with a solution....

Thanks & regards,

- K -