The free FTP hosting service is designed for personal and casual use only. A typical free usage scenario is a user use an FTP client such as FileZilla to upload / download some files. The free service is limited to 25 logons per day, 2 concurrent connections.
If you use the service for business, or if you use any automatic software / scripts, then you need to order a subscription, which starts at only $1.99/month.
To trouble shoot your problem, please stop your scripts and wait for 1 hour, then use FileZilla to logon ftp.drivehq.com. Most likely it will work fine. If not, please email us the FTP log / error message.