As dale said, you may be encountering interference from a cordless phone or such other wireless device using about the same frequency. You can force you repeater to use a specific 802.11b or 802.11g mode, you may also want to try forcing it to use a specific channel. Repeaters and AP's will change channel from time to time to get a better signal. I assume also that your repeater is getting a good signal from the outside wireless source. Can you look at your repeater recieving signal strengths? You have repositioned it though, maybe try a place closer to the uni source but not too far away from you. Your goning to have to play with locations abit. If you know that it is recieving a good signal, then concentrate on finding a channel that works for you and force it to use only a "b" or "g" mode. Your laptop should show a strong signal without changing speeds etc. Remember you essentially now have two wireless networks, therefore possibly two speeds. Ensure you are only connecting to your repeater only. Make sure that the uni wireless is not set to connect automatically as you may inadvertetly be disconnecting from your repeater and back to the uni and so forth however this is highly unlikely as your repeater is so close.

Luck,

Reuben.