Placeshifter channel bandwidth too low

[marneb17]

I am using the placeshifter client for some time now.
It works quite well, but since I got a faster connection I have a problem, that the available bandwidth isn't used.
I have a 16Mbits/s down and 1014Kbits/s up connection. When I ftp I can get a reliable speed of about 120Kbyte/s upload. Whether I connect to another computer in my city, or on the other side of our planet. The ping on the other hand rises a "little" bit.
But using the same connection with placeshifter I see a lesser bandwidth. For inner city connections, I see a channel bandwidth of about 650Kbits/s. But for connections to Hawaii it will only use ~300Kbits/s. Setting the bandwidth manually results in stuttering.
I have also tested on the lan, that the server is capable of transcoding to 2Mbits/s. So it is not the server. Nor is it the connection, as the ftp proofs.
I think it has something to do with the ping times, but it shouldn't because placeshifter shouldn't rely an answer to estimate the channel bandwidth.

This problem was observed with the v5 and v6 placeshifter.

Do you have the same problems, or can you use all of your upload?
Marneb