Searching breaks connections

I have recently installed a wireless router (Philips SNB5600) with a USB-adapter (Philips SNU5600) and have been dumbfounded when trying to get the block away from LimeWire. Mainly due to bad explanation from Philips Customer Care and software that didn't come on the installation CD. After having gone through NAT-programming, port-forwarding, different settings of LimeWire and such, I finally got rid of the brickwall.

But the biggest problem still exists: When I search for anything, I lose connections. I never lose all of them, but when I'm connected to three Ultrapeers and search for something, I more often than not lose connection with two of them. Is this normal for wireless networks, or is it just my setup?

OS: XP Pro SP2
CPU: P3 1.26 GHz
RAM: 1536 MB
LW: 4.12.6 Basic
Linespeed: 1500/400
Modem: Motorola SB5101
Router: Philips SNB5600
Adapter: Philips SNU5600
Firewall: Disabled on router, Windows on computer
ISP: Romerike Multimedia (Norwegian, local, Cable)
The USB-adapter is connected through Targus USB Hi-Speed HUB (4 ports) on an ALi PCI-to-USB card (2xUSB2.0)

When I connect via cable to the modem directly to my NIC (HP NC3163 Fast Ethernet) this problem is non-existent.

Just found out that LimeWire disconnects when I'm not searching too. While writing this post, it disconnected with all my connections. It soon connected again, but it's annoying and time-consuming, not to mention it consumes a great deal of bandwidth and CPU-power.

when i download some audio files,i am being notified that a similiar file already exists
even though i know this isn't the case ex.(gospel song) compared to a (rap song),is there a way to somehow dispose of this and correct it's functioning