Okay, I'm using 1.6 with power management turned on and just read a 80 pages of the above comic without any issues at all. I was plugged in to my computer via USB and I waited about 20-40 seconds between page turns this time. I'll update this post after trying the same while not plugged in.
Update: Continued reading 80 more pages in the same fashion but without being plugged in, and I
still have no trouble. Perhaps the problem lies with your specific DR, or the image format? Mine were standard .jpegs. Can you replicate the error if all pages are in the same folder? Maybe the memory leaks occur when you open/close documents. Beyond that, I'm stumped
Note: Another change I had made is that I had modified my /apps/er/sys/power/sec_suspend value to 3 seconds in dr1000.ini in the System folder on my SD card. I don't even know if the DR looks at this value in 1.6, so I doubt it made any difference. Also, in case you're still stumped, how about trying to install 1.5 to see if the bug persists? Re-installing 1.6?