I've had mine around the same time and haven't had the slippage problem either, and I use it predominantly with a Variax so a very heavy bass. I like the fact it's a bit slidey on the shoulder, that was a main concern when buying it. I hate straps that grip your clothing and drag your top over your shoulder, nothing looks worse than a sharp suit getting all rucked up, I do like to play with my bass at various angles though.