Question:Why can't my friends upload files any faster than 32 KB/s to my server?!?
Well, since the beginning of broadband in the US, providers have been incrementally increasing the bandwidth delivered to customers; but only for downstream (aka Downloads).
Upstream is often capped by ISPs to anywhere from 128 KBit/s to 1024 KBit/s (1 MBit/s). This will affect upload speeds, even though the line is cabable of downloading multi-megabit/sec.
Unfortunately, there's no way for BulletProof FTP Server/Client to circumvent this cap, as it's being limited at the lowest possible level in the TCP/IP protocol.