Hi,
I see those download & drop after a few seconds quite often. This happens not only at startup also everytime you have some free slots for uploaders. I have it on my list for reporting possible Xolox bugs, but wanted to wait until Xolox team had fixed some other problems.
I never mentioned this behaviour with other Gnutella clients (e.g. Bearshare) and I think it might be a communication problem between Xolox and differnet clients. Propably another client drops the connection because the data stream is too fast or too slow?