i had word back from the vbulletin team on this too. it seems that the spaces must have been added during the upgrades. but that if the same code is added in now, it should work fine.
one thing i did notice though, is that when i made a test post to try this out, in the preview mode, it still had the errors, but when i clicked to send the post, it appeared just fine. ive asked them why this happens, so i'll let you know what they say. but for now, the end result does work fine.
im afraid the only option is to go back and re-code the old posts. editing them and deleting the dud code, and adding the fixed code. sorry about that.
susie