Hopper Bug

[iNook]

It has come to my attention that there is a large bug with hoppers, sometimes they will just stop. I've checked my storage system plenty of times and I can assure you there is no redstone signal touching any hoppers (besides filters)
This is causing backups in storage and the bug just makes the hoppers freeze. Not sure if this is 1.8, spigot, spigot + 1.8 compatibility, plugin compatibility, no idea, but its extremely annoying. Theres only 1 fix, which is break and replace, which again only works for 10-15 minutes.