Internal IP address automatic change

[lacsap]

For some unknow reason, the internal IP address of my computer changes by itself. (about every 2 months)
It changes between 192.168.0.2 and 192.168.0.3
It happens on my desktop (XP SP3) and laptop (Vista) at the same time. While the last number of the address of my desktop goes from 2 to 3, the laptop goes from 3 to 2 and vice versa.
My router is a Netgear RP614v2

I'm probably the only one in my house who knows how to change the internal IP address, so I don't think someone changed it manually.
I want to know why it's happening and how to solve it.

It's annoying because I need to change my port forwarding settings every time it happens.
Thanks for the help.

[Duki3003]

Unless you're actually having a problem with BakaBT (I don't see why internal IP would cause you any such problem) this is a technology thread.

[DaggerLite]

Your router assigns you an IP from a pool of numbers you set, e.g. 1-100. The first computer that connects gets IP 1, the next gets 2, and so on. If address 1 disconnects and a new computer connects, the new computer takes over address 1. If you want your IP to be remembered, make the router reserve it for your network card's MAC address.

BakaBT does not know your internal IP.

[lacsap]

Thanks, I reserved my network card MAC address, it should stop doing that.