Difference between "bugs" and "customer issues"?

Just curious... I mean, I find bugs, here and there, most of the time, if I can, I work around them, or whathave you.

Some, if I actually think they are related to your product, vs something I did, I post a bug.

However, (and I'm not the only one, I see other bugs files), since I have a concern of a feature that's not working right (spamassasin), when would one file a "customer issue" vs. a bug?

Jes' curious, since I cannot add a "Me too!" to someone else's bug... (which I think should be allowed..)