Motherboard - unknown, HP Pavilion dv6 Notebook PC
Processor type and speed - Intel Core i5 CPU, M480, 2.67GHz
Amount and type of RAM - 4GB
Video board w/ RAM amount and type - Generic HP Pavilion Laptop - no extras
Sound board - IDT HD on board sound
Operating system - Windows 7 Home Premium
Game name (and version, if applicable) - Duke Nukem 1
Description of problem - This isn't actually limited to this game. Whenever I use DOSbox I can play a game quite happily for about five minutes, and then all of a sudden my screen flips from landscape to "Portrait (flipped)" and it's a pain in the butt trying to get it back to normal. This continues whenever I use dosbox.
Reproducibility of problem - All the time. This issue is NOT limited to this computer. I have used dosbox on several different machines, all with the same result.
Sound mode used - built in speakers - no sound issues however
Video mode (Software, OpenGL, Direct3D, or Glide, and resolution) unsure
Version of emulator (for VDMSound, probably 2.0.4 or 2.1.0; for DOSBox, 0.58+) using Dosbox version 0.74
Steps already attempted to solve the problem - none. I can't seem to find any details on lord google about this issue hence why I am here.

Hope this information is helpful. Any advice would be much appreciated.