minor afflictions

hey,

its not the first time i get some minor errors using the intersection methods. can somebody tell me why that is? i don't know the problem behind this. i attached a file showing a brep brep intersection but the result has one corrupt element (the line ends not within the surface that was actually intersected with another surface which actually shouldnt be possible) and therefor is useless to work on. i will have to work around or use vb script now as i did last time when i was facing a similar problem.

just wanted to ask if this is because of the development status of grasshopper which is not finished yet or for what else reason and maybe some advice how to prevent something like this to happen?

thx!