When trying to place a button, lever or a door on a reinforced stone block, it disappears.
For instance: If I try to place a door I see a half door for a couple of seconds, then it disappears.
If I try to place a button it disappears immediatly.
Red rectangle == button location.
This does not happen in SSP, only in SMP.
SMP mods used:
ModloaderMP 1.1 v2.1