How long does it usually take for a block to get solved in slush's pool?
At this difficulty, a few a day. Go to the Statistics page at slushes pool to see found blocks. The last block took 4,067,397,930 shares to find. A 1759 share contribution is very small percentage of the total shares. (0.0000432%) May I ask, what hash rate are you contributing to the pool? Your hash rate will have to be measured in the GH/s to see any rewards. At the current difficulty, a 2.8 GH/s rate will see about 0.0008 BTC a day in rewards.
EDIT: Oh I just noticed... GUIMINER!! LOL are you trying to mine with your CPU? If so, you are burning more in electricity than what you can mine with that program. The difficulty has exceeded the capability of CPU mining. (and GPU for the most part) You may want to try your luck at mining altcoins.