How do you stop a shower head slipping down?

[Mercedes]

Hi

We've got a shower head on a bar and its recently decided not to stay up but to slid down the bar to the lowest bit- bit ackward when you either have to squat in the shower or have a shower with one hand in the air holding it up.
To move it up and down there a grip thing at the side that you push to move the head up and down if you see what I mean and then when you release the grip its supposed to stick.
The grips obviously not working but I can't figure out an easy way to sort it out without replacing the whole bar and grip which seems ridiculous.
Has this happened to anyone else and how did they resolve it?

It's not attractive and I guess we are fortunate as DH and I are the same height but we hold it up with some duct tape wrapped around the bar! It's been like that for nearly two years - it's on the list of things to replace but it's worked as a stop gap in the meantime so well that we haven't got round to buying a new one!

Message withdrawn

I did think tape might be the answer but I thought we can't be the only people this has happened to and there maybe another solution. I might try the blu-tack first - as we've always seem to have loads of that lying around.

sellotape