I think Toee counts entangle as a paralysis effect, Undead are immune to paralysis. --Livonya could this be changed to a web effect?
Allyx - I don't think it could be fixed. Most of the actual spell effects are hard coded. You can change the spell to actually be casting web but with the entangle graphics (I think) but then you would get other problems like being able to burn an entanglement, etc... Though there might be a way to trick the system into doing a fix. Many times the solution I have used to solve problems are often just sleight of hand tricks where I am not actually fixing anything but just making it appear fixed. - Livonya