Modifying Icons

We had gotten icons designed for our desktop application: SQLyog. The icons are available in layered psds. The designer who did the icons abandoned the project abruptly after a review. The icons are looking very good if they are seen stand alone. But, are looking bad when used in the software. They probably lack enough contrast to make them look good against a light grey background(the default color of menus in any software). Frankly I don't know what makes them look bad, but anyone would have a similar thought. I want you designers to comment on that. Because if you don't understand what is the problem, you will never fix it. Attached is the jpg of the collage. The winning bidder will be given the psds of the collage so that he can start his work from there. Finally icons of dimensions 16X16 & 32X32 have to be sliced out of the psds. Please bid only if you can work with strict deadlines.