Ovidius...like many, you are a tunnel-vision investor, IMO. Any crisis that effects the economy, ie., the present credit problem which is quickly becoming global, can effect your stock. Worse case, companies cut back on expenditures, new medical procedures or equipment put on hold to conserve cash, etc., etc. Not so OT and good to point out especially on a weekend when other news is slow.... Many times if your stock isn't performing like you think it should, take a look at the markets in general and especially the sector of your investment...ALL come in to play at times. May not prevent a stock from going up, but can effect how far it goes....
Cash is King until further notice!!!
My comments on companies are usually my opinion of long term success (years). The PPS may go up or down greatly in the meantime depending on the number of greedy suckers with money.