PORT : Connection lost

[Psi]

3.2.0 build 1080

Program looses connection during searching through the server
(Find Files on FTP)
- always at PORT command like this :

[R] 257 "/htdocs/" is your current location
[R] PORT 192,169,27,15,18,156
[R] Connection lost: admin KDM

The timing seems to be always similar, 1-2 minutes after logging.
Tried virtually everything, active / passive / noops - no result.

No such problem while standard transfers.

Thanks for your help

Psi