FileZilla connections fail using Old/Pre-installed clients, but not fresh installs

[JPP]

FileZilla (newest versions) fails to connect to a VSFTPD server (2.1.2) using the standard timeout of 20 seconds in standard FTP mode on Windows XP machines. Clients never 'touch' the server as far as server logging is concerned and shows 'connection timed out could not connect to server'.
Server is running RedHat Enterprise v5 patched as needed. Kernel: 2.6.18-92.1.22.el5 #1 SMP

1. Increasing the client side timeout to 30 seconds allows the clients to connect, but directory displays and other actions are sluggish.
2. This occurs on previously installed and used FileZilla clients, even those that have been uninstalled and reinstalled.
3. NEW/Fresh (never before installed) installs of FileZilla on Windows XP/Vista machines connect to the server quickly and flawlessly every time with the stock 20 second timeout.
4. We have turned OFF firewalls on the server side, no effect.
5. Disabled firewalls on Windows machines, no effect.
6. Using other FTP clients (cuteFTP, NCFTP, and command line clients) on the effected machines provides clean/quick FTP connections. Only FileZilla seems to have this problem.
7. This is occurring from various locations, and connection types so its not related to a particular network or location on the client side.
8. Problem can be reproduced every time.

[Tim Kosse]

Are you connecting using an IP address or using a hostname?

[Alexander Schuch]

No reply for more than 28 days. If you still have that problem with a current version of FileZilla, please do not hesitate and re-open this issue. Thank you.