I think I have reported this thing some time ago but did not find it. A document contains a very small text inside a group with a big zoom factor. Safari (and Chrome) does not render the text. This bug is visible in Safari 5.1.1 You can find a test page at http://elrond.aspix.it/tests/webkit.xhtml As default render please open that link with Firefox or Opera
The problem with your example appears to be a leading space in the 'x' attribute of <text>: <text x=" 12.8333335" ... ^ After removing that, the number rendered for me. I remember seeing a discussion about leading spaces in value attributes on some other bug, and the conclusion was that according to the spec they're not allowed.
I verified this, all works fine after removing the leading spaces. It seems that leading spaces are allowed only in list attributes like d in path.
I think Comment 01 clarifies the issue with the test case for the reporter and then reported confirmed in Comment 02 that it fixes the issue for sample case. Can this be marked as "RESOLVED INVALID" or "RESOLVED WONTFIX"? Thanks!