I have the same issues, I added the jquery-ui plugin and the console outputs the following related to the dep graph,
Uncaught TypeError: Cannot read property 'left' of null jquery.jsPlumb-1.3.9-all-min.js:1
ax jquery.jsPlumb-1.3.9-all-min.js:1
ad jquery.jsPlumb-1.3.9-all-min.js:1
connect jquery.jsPlumb-1.3.9-all-min.js:1
(anonymous function) jsPlumb_depview.js:90
e.extend.each jquery.min.js:2
(anonymous function) jsPlumb_depview.js:84
o jquery.min.js:2
p.fireWith jquery.min.js:2
w jquery.min.js:4
d jquery.min.js:4
The offending line being,
var bA = ah[this.sourceId], bz = ae[this.sourceId], bv = ah[this.targetId]...bJ = this.endpoints[0].anchor.compute({xy: [bA.left, bA.top]
this.sourceId and this.targetId are undefined.
Which version of the jquery and jquery-ui plugin are you using? Can you see any javascript errors when you open a console (Firebug/Chrome)? What browser are you using? Could you send me the JSON representation of 0.7 and 0.8?