If I want to buy BTC with PayPal, so I buy SLL, then use the SLL to buy BTC, how much money would I lose in the process?

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1. Given the current nature of addresses, how many total addresses are possible?
2. How many addresses currently have bitcoins?
3. How many addresses with BTC will it take for it to become profitable to generate addresses at random and check their balance, then send all of its coins to another address?

For #3, assume that the addresses are being generated as fast as possible, i.e. without any regard for security. The private key might as well start at a random seed, then simply be incremented. With these provisions, I think 20 MKeys/s is a possibility.

Hypothetically, if I were to send a transaction with a typo or whatever, and it had a low priority, would I be able to reverse it? For example, could I double-spend the coins involved, but with a higher T.X. fee, to an address I own?

Just wondering.

Hi, and sorry that I couldn't figure out where to post this.

Can someone please clear up this problem I'm seeing?
Lets say someone uses firstbits, to come up with something like 1Fwi3gx. From what I see in the VanityGen thread, it would not take long to generate another address with that prefix. What's stopping someone from doing so, in order to receive coins meant for someone else?

Hi all,
Whenever I try to use GUIMiner (v2012-02-19), and I click "start mining", the status bar at the bottom says

ImportError: DLL Load Failed: The specified module could not be found.

Of course, this is very helpful given that it doesn't say which DLL is missing
If I ignore that and go over to the Summary tab, under speed it says "Connection problems."

How can I fix this?