As previously mentioned in earlier posts, ML CNTR just don't have sufficient staff to cope with the traffic.! I've visited the air traffic center at Melbourne, great people and a wonderful job they do, but I guess we VFR pilots just don't get special treatment, when it comes to obtaining a clearance through Melbourne.
Ozgrade, another suggestion to get to EN from BLT is to track Bacchus-ROK-EN @ 4500.
Either way you'll end up most likely being vectored around or be told to p*ss off