Hallo!
I can't explain it, but sometimes $0 didn't work for me, I think as the name of an array maybe? I wanted to have multiple instances of a sampler subpatch, and each had an array inside, but I had to rename each instance manually, because pd didn't seem to understand the $0 in this case.
I think this was a bug long time ago ... but of course you have to start in the arrayname with $0 - e.g. $0-name !
LG Georg