WRT54G Client Bridge Mode Slow

I have a Linksys WRT54Gv2 connected to a DLink DIR-601 in Client Bridge mode. (The WRT54G is in client bridge mode). I get good speeds, near the max of my internet when browsing the internet and streaming videos, but when I try to download something I can only get 10-40kb/s.

I've already checked QoS, it's disabled, and reset it a few times. I don't know what the problem is. The DIR-601 shows the WRT54G is connected at 56% signal strength, so that shouldn't be a problem.

Any thoughts on what the problem is? Why are download speeds slow, but I am able to stream and browse the internet fine? (Speedtest.net shows 5.3Mbps down and .8 up)