That sounds very strange.
I always use the 'ever ready' fuses, with 11sec delay for skip bombing and 1sec delay for land targets. If you've got the graphic effects settings turned down this might not show an explosion in the new patch, but I haven't tried this on low settings.
Basically, if you've got bombs in there and you drop them, you should blow things up quite easily.
I always press a 'arm bombs' command as a matter of course, although this shouldn't be necessary with the Brit bombs, again unless it's changed with the patch.
I haven't done much flying of the Blen since the patch. Well, I haven't done much flying............
