Check your eqclient.ini for these lines:
Code:
ShowSpellEffects=1
SpellParticleDensity=0.000000
SpellParticleNearClipPlane=8.000000
SpellParticleCastFilter=24
Post what those settings are. Sounds like having 42 clients running at once and trying to save the settings on all of them is causing an issue.
You can use this to turn off spell effects:
Code:
/showspelleffects off