> Pipe:
> No.1
> Bandwidth: 512Kbit/s
> Delay: 0
> Mask: Destination
        ^^^^^^^^^^^
To me a destination mask makes very little sense here. This will create a
dynamic rule for every attempt to use the pipe.

> Rules:
> Target: Pipe1
> Interface: Lan
> Protocol: any
> Destination: 192.168.149.45
> Direction: any
             ^^^
I would probably prefer to shape on the WAN interface instead on the LAN.
Also, since you only want to shape inbound traffic you'd want to set
"Direction" to the appropriate value ("Out" if shaping on LAN, and "In" if
on WAN).

> This config is successfull for about 5 seconds.. I can download stuff in
> 60kB/s (512Kbit/s) in about 5 seconds, after that the download goes down
> to 0 (zero). Why?

Bandwidth limiting incoming traffic is known to have strange side effects.
In this case it might be the bucket that gets filled up and causing
time-outs.

// Thomas Hertz