spring retainers

Gday folks,
Anyone ever had or heard of any troubles with the Isky aluminium spring retainers? i.e pulling through a little while bedding in or failing completely?
Have had some gain a little height after a little use. Have been led to believe they can bed in a little and will give them a little more use before calling it. But given Targa is just a few months away is over a 1000klms and they've done nothing near that they are not inspiring confidence. And I need confidence!
Cheers,
Llew
Anyone ever had or heard of any troubles with the Isky aluminium spring retainers? i.e pulling through a little while bedding in or failing completely?
Have had some gain a little height after a little use. Have been led to believe they can bed in a little and will give them a little more use before calling it. But given Targa is just a few months away is over a 1000klms and they've done nothing near that they are not inspiring confidence. And I need confidence!
Cheers,
Llew