latest test to see if it was working again :: SVN Trunk build of r35360 on Linux 64bit.. does seem to not of been working since r35342

it looks like the Compositor is no longer updating any changes you make within any nodes I add in real-time. Changes are only applied on F12 render.

Simply render the default cube, goto the compositor, use nodes, add a node 'like color-balance', add a viewer, select Backdrop. it may show the viewer node or stay blank. Adjust the color-balance and backdrop does not update, nor does the composite render result or Viewer Node.

[Render Layers] total: 10000, compile: 0, upload: 0, execute: 0, download: 0, other: 10000
[Composite] total: 30000, compile: 0, upload: 0, execute: 0, download: 0, other: 30000
[Color Balance] total: 0, compile: 0, upload: 0, execute: 0, download: 0, other: 0
[node::ntreeCompositExecTree] total: 60000, compile: 0, upload: 0, execute: 0, download: 0, other: 60000
[node::ntreeCompositExecTree] total: 20000, compile: 0, upload: 0, execute: 0, download: 0, other: 20000
[CMP_Colorbalance.CPU] total: 430000, compile: 0, upload: 0, execute: 0, download: 0, other: 430000
[Color Balance] total: 430000, compile: 0, upload: 0, execute: 0, download: 0, other: 430000
[Composite] total: 20000, compile: 0, upload: 0, execute: 0, download: 0, other: 20000
[node::ntreeCompositExecTree] total: 450000, compile: 0, upload: 0, execute: 0, download: 0, other: 450000
[node::ntreeCompositExecTree] total: 10000, compile: 0, upload: 0, execute: 0, download: 0, other: 10000
[node::ntreeCompositExecTree] total: 30000, compile: 0, upload: 0, execute: 0, download: 0, other: 30000
[node::ntreeCompositExecTree] total: 10000, compile: 0, upload: 0, execute: 0, download: 0, other: 10000
[node::ntreeCompositExecTree] total: 10000, compile: 0, upload: 0, execute: 0, download: 0, other: 10000
[node::ntreeCompositExecTree] total: 10000, compile: 0, upload: 0, execute: 0, download: 0, other: 10000
[node::ntreeCompositExecTree] total: 10000, compile: 0, upload: 0, execute: 0, download: 0, other: 10000
[node::ntreeCompositExecTree] total: 20000, compile: 0, upload: 0, execute: 0, download: 0, other: 20000
[node::ntreeCompositExecTree] total: 20000, compile: 0, upload: 0, execute: 0, download: 0, other: 20000
[node::ntreeCompositExecTree] total: 10000, compile: 0, upload: 0, execute: 0, download: 0, other: 10000