True Package, fixed line 7 Mbps.

Even swapped back to the True modem without Wifi and the IP Address still changes. Is this to be expected or shall I call True Technical Support?

The reason I ask is the IP Address is used as a backdoor to prevent bloated Google Adsense and Analytics statistics when updating my sites. The True IP Address used to change a couple of times a day but now it is ridiculous.

For Dynamic IP address,

"The IP "Lease Time" is set by the ISP and typically if your router is still online and requests a new lease, the ISP will give you back the same IP. as nothing is gained by giving you a different IP."

"Most routers/modems have a display for the WAN IP and typically will display the IP "Lease Time". It is usually a few hours to a few days. Odds are your modem asks for an IP regularly but the DHCP server simply hands it back the same address [while refreshing the Lease Time countdown]. When it has a reason NOT to, your IP will be updated with whatever new IP is being handed out." copied quotes courtesy of this website

I think most people would report their WAN IP address remaining persistent for a week or so before cycling to a new address.

WAN IP addresses can be forced to change before their Lease Time expires if you have line issues causing a line fault or experience equipment resets, forcing the equipment to renegotiate and the DHCP servers offering a different IP address.

An alternative theory would be it being set as a tactic to thwart P2P activity.

My guess is an ADSL sync problem. It maybe a good idea to check the ADSL line stats.