cydia suddenly started acting up on me. it constantly has the black bar on top saying downloading packages and the homescreen doesnt load. if i search and try to install something, it'll say running for a couple of minutes then it says "POSIX: Operation timed out" i know this isn't an internet issue as all my other apps work. even if i switch to 3g it doesnt work. i've tried rebooting and respringing but nothing seems to work. any advice?