dos attack fix plugin problem (ob 4b)

me use ubuntu linux

can't load daf plugin

error msg :
failed to dlopen /home/keris/server2/orangebox/cstrike/../cstrike/addons/daf/bin/dosattackfix.so error=/home/keris/server2/orangebox/cstrike/../cstrike/addons/daf/bin/dosattackfix.so: undefined symbol: _Z12MathLib_Initfffibbbb
failed to dlopen /home/keris/server2/orangebox/hl2/../cstrike/addons/daf/bin/dosattackfix.so error=/home/keris/server2/orangebox/hl2/../cstrike/addons/daf/bin/dosattackfix.so: undefined symbol: _Z12MathLib_Initfffibbbb
failed to dlopen /home/keris/server2/orangebox/bin/../cstrike/addons/daf/bin/dosattackfix.so error=/home/keris/server2/orangebox/bin/../cstrike/addons/daf/bin/dosattackfix.so: undefined symbol: _Z12MathLib_Initfffibbbb
Unable to load plugin "..\cstrike\addons\daf\bin\dosattackfix"

use version : ob 4b

problem modify please