I make sure that my sites get a fair number of deep links but I've still seen the # of indexed pages go up and down.
I think that's been my experience, too... Google numbers fluctuate pretty much day to day, but my rankings are generally pretty stable (for older sites, anyway).
Spider friendly being the keyword I totally agree with you. Another comment you have made were my recent findings as well. Webpages with seniority are very stable, ESPECIALLY when there are 'index' files. In the last PR update ALL my index files received the most PR increase...100's of them. What's odd about that is, in some cases these deep index pages outrank the homepage? Then you enter some of the pages within the index...they too, received a huge PR increase. Some of these sub index pages went from PR0 to PR5. Google, playing games with my head again
Sometimes google shows decreased numbers of pages before adding or updating new pages in its index. You should see some more pages withing some days.
He, he those good old relic threads. They really serve little purpose in the world of technology. Accept, of course, the wonderful people that are still DP members 3 years later . Hope all is well with you Minstrel! H