Mercedes A class steering lock issue

[DEEMAN1]

Hi,

I'm wondering if some of you experts can help...

On my wifes 2006 A class it doesn't make the locking noise when you put in or take out the key anymore (steering lock?) and the steering lock occasionaly gets stuck so you've got to whack/move it so you can turn the key.

Have any of you guys experienced this before?

I hear the ESL is a common fault on these cars or could it be something else?

Thanks