There is a known issue with transferring big files (bigger than 1 Mb) from/to SecurePlatform firewall by Checkpoint you should be aware of. The file transfer fails with some error about buffers. The problem is that Checkpoint firewall SPLAT comes with the old opensshd daemon , which has a bug in it dated 2006 ( https://bugzilla.redhat.com/show_bug.cgi?id=184357 ) causing transfer to fail if SCP client is trying to use buffer bigger than 1 Mb . And as (the only) Windows based client WinSCP (that in turn uses putty code) has been using buffer larger than that for ages, trying to use versions of WinSCP newer than 3.x results in failure .
Checkpoint have a hotfix for that, according to SK sk66195, but the less intrusive alternative is to use older versions – pscp 0.60 and Winscp 3.x (e.g. 3.7.4)