I'm posting this to see if anyone else has had similar experience and can verify my intuition.
I've been consolidating several RoboHelp files, copying the text from a few thousand topics into an existing RoboHelp file (using version 8 on Windows Vista) and then taking five or six similar topics and merging the text into a single topic to cut the total number down to about 700 topics. By the way, I spent about a a full day trying to merge them together, but could never get it to work, despite Peter Grainge's excellent step-by-step advice. It might have been because the larger file was created years ago in an older version and the update may not have been clean. In any case, the editing and consolidation needed to be done anyway.
In any case, I created 20 or so folders in the parent RoboHelp system and created new topics in each, copying text from the other (older) RoboHelp file into them. It was tedious, but forced me to read through the text and properly style it, so I considered the exercise worthwhile. I considered myself fortunate to only crash three or four times a day. Not a big deal, really.
Then, once I realized my folder structure could be optimized, I started dragging topics out of their original folders into other folders. This is when I started crashing five or six times an hour and losing lots and lots of data in the process. Many of the topics I deleted came back to life, but with an X through their icon, and many of my new or moved topics became unusable, and I had to retrieve them from a backup.
Rather than troubleshoot this nightmare, I sacrificed half a day's work and went back to a previous version I'd backed up on the server. Now I'm back to creating new topics and copying text into them rather than dragging topics from folder to folder. I'm not crashing nearly as much.
Has anybody else noticed their RoboHelp system becomes far less stable when they move lots of topics from folder to folder?
Peter's advise is right on, as usual. I had a similar experience last year in RH7 trying to rename and rearrange topics in a large project. Once I got in the habit of trashing the CPD periodically (rename it .OLD, restart the RH from the project file, then delete the .OLD file), RH stopped crashing and I stopped having to fix all those broken topic links.
Hey, that was very helpful! Clearing cache seems to have done the trick. Thanks!