Slower upload speeds in V4.2 vs V3.6

I can confirm what other people have been saying, that there is a bug in version 4.2, in fact every version since version 3.6. That is that upload speeds are WAY down. I kept all settings the same between version 3.6 and 4.0. Below is a small screen cap of netmeter. The higher peaks on the left are of version 3.6, the smaller ones on the right are the latest version of 4.2. Operating system is Windows XP, SP3. So, it is not a case of the speeds being higher and being reported lower, they actually ARE lower. Please fix this asap.

Keeping all the settings the same is not always the best thing to do.
Have you tried changing your TCP/IP upload buffer settings?

Hello,

When upgrading from v3.6 to v4.x you may find a decrease in transfer speeds, this is typically due to the TCP/IP Buffer size setting. This option is located in the Preferences dialog under Connection.

Its best to set these values as default and then adjust the buffer size as needed from there. For most servers connected via the internet you'll find the default works well, for LAN based transfers you may see a slight increase by increasing the TCP/IP buffer size up to 128 or 256.

By increasing the TCP/IP buffer size you also increase the cpu/memory usage of FlashFXP, if the buffer size is too big you may see reduced performance and temporary UI freezes during a file transfer.

This setting must be changed while disconnected from the FTP/SFTP server. Changing it while connected will not have an immediate effect and the change wont take effect until the next new server connection.

The default settings used in FlashFXP v3.6 were optimally tuned on Windows XP, however we noticed that these high performance tweaks and adjustments performed quite badly with the updated Microsoft TCP/IP stack introduced in Windows Vista and Windows 7, we also noticed that our optimal settings could lead to incomplete file transfers when combined with certain software firewalls.