intermittant no start

1998 XJ8. runs great ... strong ...quiet. i bought it used with 38,000 miles on it march 2003 since then i have have replaced the water pump, had the factory recall done on the throttle body, replaced the battery and the starter, all in the last 2 years. i love this car and am willing to pay to get it right. lately, about 25% of the time it doesn't want to start. cranks over great, just like the fuel pump is not picking up fuel or something. wait a while, couple more tries, then it works like there never was a problem. any suggestions on what that could be? it did say under the hood that it recieved a S479 reflash for hard to start in jan 2001, any idea what that was all about? could it be related? could the fuel pump be going bad and still run great after it starts?

ilove a jag that runs.