Another 99 problem

Hi I had a question on my truck, and thought someone here has had the same problem. today after loading a car on a trailer. I started my drive, got out of the driveway and the truck just bogged down pushed the petal down but no acceleration it just kinda tried to go but the rpm's would not go up. Put it in neutral and floored it to maby clear it out and it did after a few seconds. (this is my tow vehicle by the way) The fuel filter has been replaced about a year ago, and not a lot of miles have been put on since. I also have a problem when the truck is not quite warmed up yet, and that is I ll drive about 300 yards to a stop sing. Try to start to get in to the street and if there is a car coming the truck just leaves me hanging, Like I'll give it gas and nothing for what seems like forever but I'm sure its only 3-5 seconds and then it will go. I have replaced the fuel psi regulator recently and that had no effect ether. I sure appreciate any info that anyone could give me. The truck is a 99 silverado 5.3, 4x4 extended cab, and the mileage is around 67k. I have looked at all the posts that i thought were related but nothing that was definite. Although I did read something about "Safe Mode" would that be a problem?
thanks Dan

I have had the same problem with my 99 and i cannot figure it out either. I recently relpaced the fuel pump and the filter and now when i first start it after it sits overnight and back out of my driveway it hesitates bad when put into drive. Probably a second or two and it can be scarry sometimes because i live on a busy street. My truck is also used to tow on occasion.

Yep I hear that, I found that the psi regulator was bad after I would start it and it wouldn't start right away but after a few seconds latter. I found the vacuum hose filled up with gas when it sat for a few minutes. And it is not safe mode but Abuse mode i was thinking.