Hi Tonin,
The 5110 is a single band phone which only operates on the GSM 900mhz networks, such as O2 and Vodafone in UK. This means even if the phone is unlocked it can only be used on Gsm 900 networks.

If you want to use that style of phone you can buy a 5130 which is identical in design and is also single band, but this time it only operates on GSM 1800mhz networks such as Tmobile, Orange and Virgin (although my 5130 also picked up O2 & Voda??)

The problem you had with Noktool1.8 by Rolis has been mentioned by me in another post, you simply have to click the 'Auto Setup' function in the 'Options' menu when the phone is connected and switched on.