I installed a VSFTP daemon on a CentOS server, using a RSA certificate for logging in using explicit TLS. Now, I cannot upload more than 82k.

With files under that limit, there is no problem. The FTP works like a charm. But as soon as a file reaches 82k with FileZilla (81,952 bytes to be exact), the transfer will stop, and the FTP client hangs until time out is reached.

FTP client console:

15:10:21    Command:    STOR jquery-1.7.2.min.js  
15:10:21    Response:   150 Ok to send data.  
15:11:21    Error:  Connection timed out  
15:11:21    Error:  File transfer failed after transferring 82 KB in 60 seconds  

/var/log/vsftpd.log

FTP command:  Client "x.x.x.x", "STOR jquery-1.7.2.min.js"
FTP response: Client "x.x.x.x", "150 Ok to send data."
OK UPLOAD:    Client "x.x.x.x", "jquery-1.7.2.min.js", 81952 bytes, 1.32Kbyte/sec
FTP response: Client "x.x.x.x", "226 File receive OK." // NOT okay, file is bigger
// No mention of error here

I cannot find relevant info about this problem, apart from a possible problem with trans_chunk_size (not mentioned in default config), but I tried different sizes and it has no impact on the problem. trans_chunk_size=4096
trans_chunk_size=8192
trans_chunk_size=9999

Ofcourse, after every configuration change, I restarted the server:
/etc/init.d/vsftpd restart

What else can cause this?

It's not the latest version, but it's the latest update within the repositories that has been deemed fit for enterprise usage:

Package info:

$ yum info vsftpd  
Loaded plugins: fastestmirror  
Installed Packages  
Name       : vsftpd  
Arch       : x86_64  
Version    : 2.0.5  
Release    : 24.el5_8.1  
Size       : 286 k  
Repo       : installed  
Summary    : vsftpd - Very Secure Ftp Daemon  
URL        : http://vsftpd.beasts.org/  
License    : GPL  
Description: vsftpd is a Very Secure FTP daemon. It was written completely from scratch.