I have had this happen to me also, the fee was much higher than the normal 0.005 and it took the remainder of my bitcoins as the fee

Is this your tx: http://blockexplorer.com/t/7AYvrSCyRK ?
What version of the client were you running? 0.3.24?

How did you get so deep into bitcoins with out even knowing how to use block explorer? you take the address that you used and put it in block explorer and look through the transactions for the one that matches up with the date amount address etc

Because all the wiki articles are pretty awful, block explorer has basically no instructions, the client doesn't log enough info about transactions, and my bitcoin address changes every time I receive (or is it send?) a payment which makes it impossible to look at the history based on my address.  I did know the target address though but didn't know it was individualized to me, which actually seems mandatory now that I think about it

But besides that, if the client software is enforcing that policy and not the network, that's a huuuuuuuuge security flaw.  Someone's going to write a rogue client any day now that pays a 0% commission all the time and let them go through.

I thought that a transaction gets thrown out there and any pool or individual can attempt to put it into a block.  They'll automatically grab the highest fee ones first to maximize profits but if they run out of ones that have a fee at all, they crunch the free ones, possibly from smallest size to largest byte-wise.

So you can attach a fee of 0 to anything but then you'll get it treated like a 2nd class transaction that takes a lot longer to get processed.  BUT if it comes down to a client that has a mandatory fee and one that doesn't allow transaction fees to be added and 95% of people use the no-fee one, all the servers are forced to pick up crappy unpaid transactions.  And right now and in the short term future, there's like 100 transactions average in a block and like 30,000-ish miners so I don't think 0 fee transactions have a lot of trouble going through.