TCP checksum error

[malcolm mcqueen <malcolm1@orcon.net.nz>]

I have been having problems with network connections. Dropping out, and 
slow.
On investigation using wireshark, I see I have many bad packets with 
incorrect checksums.
These may not be the source of my problem but I wish to get to the 
bottom of this first.

I am running Lenny amd on a Dell E520.
The problems occur on output for various types.
Some I can see at present are:

ssh encrypted response packet, other ssh packets seem OK
HTTP GET , others seem OK
IMAP
DNS

I have tried another network card with the same result and have run 
memtest86.

Malcolm McQueen