Exactly the same problem. the rubber bits that were replaced new on my other project mini that hasn't been on the road or out of the garage for the last few years all need replacing. In fact the only parts that don't need replacing are the ones I replaced for poly, something I've also recently been doing to the daily.
Although that reminds me seeing as I have the mot on the daily due soon and the front knuckle joints I fitted from min-it's (there excuse was what do you expect from cheap parts) the rubber dust covers had disintegrated complete within 8 months. I know they are cheap enough, but its a right paint having to completely disassemble the front suspension just to replace a £2.50 part just because the rubber part just doesn't last.