the ava is not a steam problem. at least the issue i posted about.
it fails on running the plugin code in "postbit_display_start".
it's always producing an empty/broken result if the cache is outdated and actually an "update cache" should've been triggered.
when the "postbit_display_start" code actually has to update the cache it will always break and create an "empty" cachefile for the user (
see this post).
looking up the specific user via admincp or you go to your steam section in your usercp will always fix it and work correctly for the specific user respectively yourself. otherwise the steaminfo cache will remain corrupted/empty.
this leads to that an invalid image url will be build an thus the avatar shows as missing/alt-text.
i'm suspecting a path or hook problem but still i have not much clue about vBs hook/plugin system and since my "community" is practicaly dead i have no real effort to look trough the whole thing.