Another update:

After my last post, i have copied the missing partitions using the command
Code:
 dd /dev/hdbX /dev/hdcX
and most partitions were copied just fine, but some revealed more I/O errors.
These errors were the reason why i needed to move my stuff from harddisk #1 to harddisk #2 in the first place. Anyway, these errors caused some partitions to be only copied partially.
Now the partition table contains the info that partition X, let's say /dev/hdb10 is 10GB, but because it's only partially copied, the actual size is smaller than reported.
So i must reformat those faulty partitions now (i have over 20 partitions) and filecopy the contents of the decaying harddisk over to the new one.

I am copying my files from the old harddisk to the new one using Midnight Commander (to noobs like me, the command is "mc") which works perfectly. It is a lot like Norton Commander so it looks and feels familiar, but it's much better at handling errors than any other method i have tried so far.

Expect at least one more status report from me a a later time.

Again, thanks to everyone that helped!