If it was your ISP somehow at fault there would be no progress for the downloads. If you try right-clicking one of the columns and choosing extended tooltips, when you hold your pointer over a download it will say how many Kbit are lost to curruption.

Your JAVA version is quite old. I use v. 1.5 update 6 and it's working fine. There are some newer versions but I haven't updated yet. If it ain't broke, don't fix it . I would try updating your JAVA. Download the offline installer, then remove previous version using add/remove programs and install the new one (some say you should disconnect your internet while installing it). If there is no progress after doing that. Then do the same with Limewire. There has to be some curruption in one of the programs. When removing Limewire use the Start>Programs>Limewire>Uninstall option (add/remove programs is not good for removing Limewire) then do the steps in the post above as those files won't be deleted when removing Limewire. Download Offline installer not the recommended one and do a clean install.

Believe me I know how frustrating it can be when something just won't work. I'm trying to portforward my router and get UPnP to work. Must have spent about 50 hours on it now and it's driving me bonkers