Roomies can connect but I cannot

[Snail17]

I've been very frustrated (since January actually) because I have not been able to connect to any programs allowing me to download other user's files. I've tried Macster, Napster, Mactella and most recently Limewire however in each occasion all connection attempts failed--in fact, no connection at all was ever made. I live in a new apartment complex (it is now a year old) which contains a single T1 internet connection to which all residents are allowed access. My two roommates both own PCs and, though using different software, are both able to download music. I own a Macintosh and until January was able to download using Mactella (and before that, Macster). Unfortunately since then I have not been able to determine why my computer will not connect while their's will. I was initially thinking programs such as Limewire were somehow being monitored by the apartment managers and access was being denied, however I don't see how this can be the case, lol unless they really have a sore elbow for Mac owners. If anyone has any suggestions, I would definitely appreciate the help! Thanks