Why is the pathfinder not working any more ? Too many nodes ?

Question

Hi there, I use Illustrator CS5 for geographical purposes and use to make maps.
I'm making a huge and detailled map for about 6 months and discoverd last week that the pathfinder (the tool I use the most) does not want to work anymore.
In this exemple :
[url]http://img842.imageshack.us/img842/4606/help1f.png[/url]
I wan't to soustract the white shape of the yellow shape but whatever I do, it won't work.
The yellow shape is quite complex and have A LOT of nodes (I hope it's the correct name in english). Why don't you look at this unzoomed screen to check it out :
[url]http://img696.imageshack.us/img696/5958/help2q.png[/url]
Is it possible that I've reached a limit where i cannot use the pathfinder because my shape is too complicated ?
Help me please because I'm stuck and cannot do anything anymore and I'm only at 30% of all I have to do with this map.
Thank you all.

Answer 1

@Jacob Bugge :
Thanks for the advice. I've ust found out how to count my anchor points. The path used to have 30.000 anchor points and I discoverd that when cutting it, the pathfinder worked for a bit, and now I'm back to ~30.000 (31.986 exactly) and it stopped working again.
Yes i use a single path at a time to use the pathfinder.
@Monika Gause :
When I click on the small icon for soustraction (substraction?), nothings happens at all. No error message. No lag or frozen screen. Just the normal way as if the pathfinder worked but unfortunately it doesn't... 
Thanks for your advices anyway