John, I did what you said and, it worked. I now have 31.8Mb free on my 8310. Thank you.

One thing though. I deleted the BB Dimension themes that I was not using. I use a Today theme so I removed

net_rim_theme_bbdimension_icon_320x240_b.cod
net_rim_theme_bbdimension_zen_320x240_b.cod
net_rim_theme_102a_icon_320x240_b.cod <-- AT&T theme

and was unable to use my own preferred Today theme. The display showed up with no theme in Options, Themes.

I re-instated the two Dimension themes and re-installed the OS and now it works fine.

I belive that the bbdimension theme files contain libraries of video calls that are required for good operation of the device. In particular I believe that the net_rim_theme_bbdimension_zen_320x240_b.cod Zen theme is vital. If you look at its file size, it is 1.6Mb vs. 495Kb and 194Kb for the other two themes. Thsi would indicate that the Zen theme has 'stuff' in it that everyone needs regardless of what theme you use.

I ambasing this on my experience of one Blackberry but have done multiple re-installs of late and I have been very careful as to what changes I have made with each iteration of my installs.

I have two phones, an 8310 and an 8100 so I could, if asked, repeat my tests on my not-much-used 8100.