I have the same problem on Thom's Whirled of Kelly blog; and that's one where I regularly supply stuff to be posted! For some reason I don't have the issue on Thom's other blogs, either...
Since I know you're reading here, I'll thank you here for the blog. Adventure really is a great book, even if it gets repetitive in the 103-246 range (other than those 8 Frazetta issues. Now if I could just find affordable copies of the two I'm missing...)
I find it interesting just how much the book picks up around 247, and it's not just- or even mostly- the Legion. You have Kirby Green Arrow, team ups of Superboy/Robin and Superboy/Green Arrow, Green Arrow origin, Aquaman origin, all within 14 months. It's really a key part of where the Silver Age starts to kick into gear; Showcase was just one somewhat scattered title but here's where some of those ideas started really picking up speed.