MS Proxy, SOCKS4A, remote DNS

Build: 1.0.979, ID: 400002650

Not entirely sure whether this is a SmartFTP problem or an MS Proxy (2) issue.

I've set up SmartFTP to use SOCKS4A with remote DNS to penetrate our Proxy. I'm getting the following sequence:

Resolving host name 192.168.x.y...
Resolving host name
Connecting to Proxy (192.168.x.y) -> IP: 192.168.x.y PORT: 1080
Connected to Proxy (192.168.x.y) -> Time = 0ms
SOCKS4: permission denied.

The proxy currently has very soft permissions and "everyone" has full rights.

1) Is it relevant that the error shows SOCKS4 and not SOCKS4A? (I don't expect SOCKS4 to work)
2) To what has permission been denied?
3) Is there an option to create a detailed SmartFTP log?

The following may cloud the issue(!):

When I connect with the same settings using Ace3free I get:
Connecting to on port 21. Attempt 1 of 3...
Connecting to SOCKS 4A firewall at 192.168.x.y on port 1080...
Successfully connected and logged into firewall
220 FTP server ready
USER anonymous
331 Password required for anonymous.
PASS *****
530 Login incorrect.
USER GoodLycosUser
331 Password required for GoodLycosUser.
PASS *****
230 Welcome to Tripod UK.

...In other words, a successful connection but something iffy in the middle.

Any help to resolve this would be much appreciated.