Rob1n | # 21 | 2011-01-11, 08:38 | Report

Is it actually changing user? Do you get the # prompt instead of the $ prompt?

mdziaf | # 22 | 2011-01-11, 09:26 | Report

I did get the # prompt instead of the $ sign last time I tried it.

Rob1n | # 23 | 2011-01-11, 10:26 | Report

Okay, so that's working at least.

The "sudo gainroot" shouldn't be asking for a password though, so the next thing to do is check whether the sudoers entry is correct - what's the result of running (as root) the following?:
As for the lock error, you can try checking for applications holding the lock file. You'll need to be root, and have lsof installed (not sure whether it's standard or not - it's in the Nokia SSU repository though), then run:
If that doesn't list anything, I'd also suggest checking rootfs space (df -h /) - it may well be unable to lock the file if there's no rootfs space free.

mdziaf | # 24 | 2011-01-11, 10:35 | Report

Ok I will get my girlfriend to do that when she comes back..will update you..appreciate the help

mdziaf | # 25 | 2011-01-11, 13:33 | Report

Running the code gives me the following:

Rob1n | # 26 | 2011-01-11, 14:22 | Report

That's okay anyway - it specifies NOPASSWD so it shouldn't be asking for any password. What about:
If that only gives the exact same result, can you post the contents of /usr/sbin/gainroot (cat /usr/sbin/gainroot)?

mdziaf | # 27 | 2011-01-11, 14:30 | Report

Rob1n, I appreciate your help with this matter. but I I wont run the code, as when I tried apt-get install preenv, we were able to download and install the application. Since this was the original aim to root the N900, I feel theres no need to delve deeper into the problem.

Again many thanx to everyone for your help Appreciate it a lot

Char | # 28 | 2011-01-11, 18:14 | Report

so the problem WAS probably apt-worker