Can't install Passenger for Apache

To set up Passenger some packages must be installed, for example libcurl4-openssl-dev:

user@ubuntu:~$ sudo apt-get install libcurl4-openssl-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libcurl4-openssl-dev : Depends: libcurl3 (= 7.21.3-1ubuntu1) but 7.21.3-1ubuntu1.5 is to be installed
                    Depends: libkrb5-dev but it is not going to be installed or
                             hurd but it is not installable
E: Broken packages

What to do? If I try to install them manually, they reveal their own unmet dependencies etc, etc.

sudo apt-get update

didn't help.

Adding maverick-security repository by adding

deb http://security.ubuntu.com/ubuntu maverick-security main universe restricted multiverse

in Synaptic Package Manager and then sudo apt-get update didn't help too.