My friend entry for "Kalin" appears to decapitalize to "kalin" after a certain amount of time (will investigate further the specific period). In this lower-case state, I'm not informed in the chat log of Kalin's entrance / exit, nor does the entry in my friends list ever appear bold to indicate that he's online. I haven't investigated whether I can chat with Kalin via this greyed-out entry, but will test at the next opportunity. edit: I currently have both lower-case and upper-case versions in my friends list, so we'll see what happens
Here's what is happening: I created my account originally as "kalin", but I always log in as "Kalin". This means that the tutorial prompts always call me "kalin" but I appear in chat as "Kalin". It sounds like your friends list is using the lower case version whenever I'm offline. I have no clue how you managed to get both version at the same time.
More details: - the entry changes from "Kalin" to "kalin" when I logout/login - only "Kalin" appears in profile search when I have no entries and Kalin isn't logged in - only "Kalin" appears in profile search when I have a {"kalin","Kalin",both} entry and Kalin is logged in - the "kalin" entry does not appear to be linked to Kalin's status, always indicates logged out