WHY does BS only Connects in Ultrapeer mode

we all noticed, that Bearshare only connects when forced to Ultrapeer mode.
I just don't understand why. in Limewire you can connect without forced Ultrapeer.
For me this is a little bit stupid because this sounds like "every Bearshare user is an Ultrapeer", so dont say, that there aren't enough UltraPeers arround
In this forced Mode I'm unable to connect to as much peers as BS likes to connect and I don't know why (I get maximum 16 of 26).
Try this:
- open Limewire and Bearshare at once (on different ports of course, BS NOT in Forced ultrapeer)
- watch that limewire connects and Bearshare not.
- Copy IP Address and port from a connected peer from limewire and insert it into Bearshare.
- watch that bearshare now connects to the peer

So why the hell does it works if you copy and paste hosts manually from LW to BS?
And another Question: Would it work if BS uses the same Connection cache as LW?

From what little I know & can say from my perspective only:
The connection caches are a little different. Also, LW 5 advanced their connection technology by self-seeking & finding fresh ones to update the cache with, whereas BearShare does not have such an optimized system. LW 4 suffers a similar issue as BearShare.
Likewise my BS connects to 16 UP's in general, so I don't think it's anything to concern about. I find my Bearshare 5.1 beta connects to other BearShare UP's mostly, which IMHO is preferred. The LW 4 UP's tend to be spam UP's or connected to a lot of spam users corrupting searches with rubbish results.

There are other BS Pro or 5.2 users out there who appear to connect well as my connection window shows.

I have no idea why when forced UP is turned off, BS struggles with connection, but quickly succeeds when forced UP is re-enabled. I'm sure someone can suggest the reasons about this & your other questions.