Finally got round to upgrading the blog from BlogEngine.NET 1.2 to 1.4.5! Everything seems to be working ok, so it looks like I haven't broken anything which is a good thing but if anything appears amiss please shout!
Rebooted the server today and it appears to have re-published all of my previous posts (that's right all 10 of them ;-), so my apologies if you thought I'd suddenly become a prolific blogger!