So I've seen this posted in other places around the web, including here: Re: After Effects CS6: Cache and Reload Footage Problem so I know I'm not alone in my frustration.
Disk cache is a fantastic thing when it works right. When it doesn't it's a nightmare. Sometimes, keyframing certain effects seem not to register with AE as a change that requires re-rendering, so you get glitches in effects where either individual frames stay the same as before you update them, or sometimes even entire layers. Particular is especially guilty of this, but I've encountered it in other 3rd party plug-ins like Element as well as built-in stuff like time remapping. There seem to only be two solutions: Edit->Purge->All Memory & Disk Cache... ; or renaming and replacing the source footage. Obviously the latter is impossible when working with a solid, and the former doesn't always work, making this a serious issue when it pops up with Particular or Element, etc.
I've encountered this at home and work, on both Windows 7 and OSX, and only started two years ago in CS6 when the Disk Cache was implemented. Personally, this drives me even more nuts because at home I've got a 250GB SSD dedicated as my AE disk cache. It's maddening to have to purge it, the whole point of having a cache that large is to NOT have to purge it very often. I suppose disabling Disk Cache might be a work-around..but frankly that's unacceptable, especially when you've got a dedicated drive for it like me.
Adobe really, really needs to address this. So please, if you encounter this problem yourself, do as I did and submit a bug report!
Adobe - Feature Request/Bug Report Form
Hopefully if enough people drive this home they will do something about it.
Apes together strong!!!
I wonder if this is Adobe, the plugin makers, or a little bit of both. It seems like the blame would fall on both sides.
Either way, you're right. That's awesome. Hopefully that'll be a fixer soon.