The 0.18 is the model 6 while 0.13 is the model 8 of the 2100+. I had asked both AMD and Asus on the issue, AMD DO NOT recommended to run the 2100+ model 8 on the A7M266 but the feedback from Asus is okay if I use the BIOS version 1.07. On the other hand the web site of Asus said the A7M266 with BIOS ver 1.07 ONLY support the 2100+ model 6. Besides, when I checked with the local Asus support, they also NOT recommend to do so. There is a post in this chat room before, they also got your result, the 2100+ do not work with the A7M266.