I also use garena, also on version 1014 and me and everyone I know can't see achievement messages either. I formated pc a couple of days ago haven't got all achievements, only got like 30 or something in about 15 different servers and I never saw one single time the message saying the I got an achievement. Neither have some friends of mine who have also formatted or reinstalled.
Btw what do you mean by localserver? All server I know (mine and friends of mine) are created using "mp_gamemode XXXX" and "map l4d_XXXXXXX"