UKBA delay in deceision making process

hi guys,

I am new to this forum and need some assistance and advice from you guys. I have recently applied for entrepreneur visa to ukba. I received my acknowledgement letter and bio metrics letter together. I gave the biometrics same day. After one week of the biometrics I received a letter from the home office which says

" we normally decide an application within eight weeks from the date of application but your application raises exceptionally complex issues and we require further time to consider your case thoroughly and reach a decision" .

Now my question is

" what are these exceptionally complex issues"

it is necessary to mention here that my ten years will be completed after 20 months from today and I will be entitled to ILR.

did any member of this forum experienced such a situation. your assistance will be appreciated. thanks