Just documenting my symptoms in case it helps solve this...

My N800 boot now takes over 2 minutes to get to the point where the blue bar starts across the screen. Running OS2007 4.2007.26-8.

I have installed quite a few apps over the last week, but no Kagu or Videocenter on this unit. Standard Opera browser.

I don't seem to be short of device memory... 18MB used, 137.7MB available. And internal memory card (the one shipped with the N800) is 65MB used, 55MB available (I allocated 64MB to virtual memory). Available virtual memory is 112MB. No removable SD card installed.

The only process I have caught occasionally maxing the CPU for any period of time is "pdflush".

I probably won't reflash at this point... I'll wait for OS2008 and do it then.