AdobeDE on Bebook
Thanks for info. I should have mentioned that the ebook I had trouble with was an omnibus with 3 volumes. The 'catalog' obtained by the no. 7 key allowed me to select which of the three volumes I wanted to read, but when in that specific volume the no. 7 key did not work with its TOC but rather went back to the TOC of the omnibus. Thus the only way to advance within a specific volume was page-by-page, or with Goto page number (but I got an error - going to the correct page but from a different volume in the omnibus). I tried a second omnibus and had the same problem with the individual volume TOCs.
The TOC seemed to work fine on single volume epubs. Thus the problem seems to reside with multivolume ebooks, those that mobi handled very well.