system plugins/vix(no module named tarfile)

system plugins/vix(no module named tarfile) this is a message I receive when first going into plugins via men? any ideas chaps? ive had the vu duo about 4 weeks now and overall im still getting used to it lol lots of wee things to play about with however on another note is there anyway we can view mms channels ? seems to be a few however they are black when I go onto channel and nothing appears ? any help appreciated cheers guys
rab