Hmmm, Im not quite sure what's up with that particular thing, but I've known lcp installation problems to occur if there are a lot of LCP's installed locally. Do you happen to have a lot of content packs?
you know, I do currently. I was evaluating a bunch of 3rd party LCPs at once for balance to get my next campaign prepared.
I also realized I was using a preview version of C/C 3.0, which obviously is not the same as the stable release version haha.
Hopefully in the future if someone googles the same issue they'll find this ;)