I keep losing in my bids for REO/Foreclosure properties...

What am I doing wrong? I've lost 6 REO properties in the last 8 months. I've worked with two separate Realtors, gotten advice from more experienced investors, etc. It just doesn't seem to work out. When placing an offer, I have had market analysis done and put forth my best foot each time with no luck.

I'm wondering if there is some type of "underground" network involved locally, where you just have to be in the inner workings in order to secure these properties? I've been told by both my realtors that the listing agent does not disclose the top bid, and I know that this is against the "rules", but I'm just wondering if certain people just happen to be more "in the know".  If so, where can I find one of these people? :-)