i was having all sorts of trouble with lsl script that contained timer events in them using up all of (and more) of the servers cpu limit, I restarted OpenSim using the [  DefaultScriptEngine = "XEngine" ] flag in OpenSim.ini and the issues seemed to resolve – or atleast everything is a whole lot more stable, though i still seem to need to restart the server about once a day to keep things runnig at their peak. (wonders if a script can be written to do this at a convenient time)

next: try comparing scripts running in C# and lsl