I am also having this error. I have to use the dosbox (0.63) to play these older games, and have tried several things suggested to me over at VOGONS, but they didn't work. (You can link to my post on the problem and their suggestions here: http://vogons.zetafleet.com/viewtopic.php?t=11118)
I have also tried the suggestion of adding the EMM=RAM found here, but that did not fix my problem. Can you suggest anything else I can try?
In case you need to know, my computer stats are: 2800+ AMD Athlon XP Processor, 80 GB hard drive, 512 MB DDR SDRAM, Radeon 9200 video card (128 MB DDR, AGP 8x/4x), and (I think ) NVidia NForce sound card. I am running XP and have Dosbox-0.63.