Sprint 1050 ST 2006 Starting problems after running out of fuel

I foolishly ran out of fuel yesterday just 50 yards from the petrol station so I pushed it the rest of the way and filled up, when I tried to start it again I had to turn the ignition off and on again about 30 times before I got it to start again, al was good and I used the bike several times that day without any further problems.
I awoke this morning at about 8:30am and went out to start my bike and found that I had to turn the ignition off and on again several times before it would start (the bike normally starts first time) I was a little puzzled but went on my way and all seemed well, after arriving at my destination I left the bike in the car park for about an hour and a half and when I returned I had to turn the ignition off and on again several times before it would start. After arriving home and leaving it for 3 hours I went to start it and had the same problem.
It seems that after I have left it for any length of time I have problems getting it started again, like there is a lack of fuel pressure at the injectors. If I turn it off after I have had it running and start it again immediately it works fine, the problem only occurs when it has been left a while.
Please can anyone make any suggestions as to what may be causing this?

 

Ahh, I was wondering where it is located. I shall drain the tank and inspect it. I suspect that you may be right though. Thanks for the info, I will post the results of my findings on here so that it may be of use to others.

 

Update.
I have been out to the garage and removed the fuel pump assembly from the tank and removed the fuel pump from the assembly unit, tested it and it is working just fine.
The battery is on charge a the moment and not in the bike so I can't see if it will start at the moment, but as I did't find a problem with the pump I suspect that I have not yet found the problem.
I will give another update tomorrow when the battery is fully charged and back in the bike.

 

Ok, so I went out and put the battery back on today and it still won't start. Even though I checked the fuel pump yesterday I was only able to confirm that the motor was spinning, Not that it actually pumps any fluid, so I guess that the impellers could still be damaged. I have ordered a new one it should arrive on Monday. Fingers crossed that will fix the problem. I will let you all know.

 

Finally got to the bottom of the problem. I bought a new fuel pump and this did not fix it, I discovered that there was no power going to the pump, this was due to a faulty fuel relay which had dirty contacts inside. After removing it and giving them a clean with some fine sand paper all is now fine.
Thanks to all who posted in this thread.