Definitely!! Not only on Sunday nights, but anytime I have a little bit of time off and am enjoying myself. It's particularly bad for me during the summer--absolutely the last place I want to be in the summer is in an office, away from the sun and the outdoors. I find it really depressing to spend day after day behind a desk when the weather is gorgeous.
One thing that helps me with the Sunday blahs is spending early Sunday evening working out really hard--I find that by the time I'm done, I don't feel so blah anymore because I've done something for myself that I really love to do.
I also have a lot of problems coming back from vacation or even a long weekend--the dread process starts even a day or two before my last day, which kind of stinks. I don't have a cure for that yet--I get really blue when I'm having a great time outdoors and suddenly realize that on Monday (or whenever) I will be back behind a desk.
It's good that you like your job--maybe the dread is a leftover effect from the "back to school" blues when you were a kid? Me, I am particularly unhappy with my current job and also the direction my career has taken overall. Oh well.
