I spent more than a year hearing nothing back from agencies last year. Applied dozens times through jobserve and never heard back there from a single employer. Put my CV up on monster and had two interviews 3 days later, both of which accepted me.
I know that probably sounds like spam, but there's no other way to phrase it, I couldn't believe the difference. I was almost ****ed off for not trying there before, but you can't really be - was just overjoyed to get a job back. Having said that, since then my (new) firm's been trying to find people via monster and had nothing but spam applications back. Weird.