I've been running MySQL 3.23.47 on Linux 2.2.17 with no problems for quite some time now.

Yesterday, however, I tried to connect to my MySQL server over the network from my Windows box (using a custom client application), and received the error:

Can't connect to MySQL server on '[ip address]' (10061)

(For those who don't know offhand, 10061 is the winsock error code for WSAECONNREFUSED.)

Upon trying to telnet to the MySQL box on port 3306 from the same Windows box, the connection is refused, which would indicate that either the server isn't running, or my IP has been blocked altogether. (I'm the administrator of the server, however, so I know the IP hasn't been blocked).

The strange bit is, the server definitely is running. I can successfully connect to the server from every other box on my LAN, and from the MySQL box itself.

Stranger yet, I started up an application I wrote last year, and tried to connect to the same server (from the same Windows box as above, using the same username/password), and it works fine! But that's the ONLY way I can establish a connection to the MySQL - using that one, specific program. All other attempts to connect to port 3306 on the MySQL box are refused. I can still access all other services on that box(SSH/HTTP/FTP/etc) from my Windows box.

I've never seen anything like this before.... any suggestions??