Thanks for your example link. The problem does occur in the devel version. Your example differs from mine as ALL instances of "//" on the page after the last opening italic "//" are preceded by a ":". This highlights two problems:
(1) the hack for bug#384 can fail under certain circumstances
(2) a pattern mismatch between the italic opening pattern lookahead (for exit pattern) and the actual exit pattern. The exit pattern will match any "//" that isn't preceded by a legitimate link schema because the link pattern gets tested before the italic exit pattern.
Problem in devel version can be seen at:
The ideal fix is to include all allowed schemes (from link syntax) in the lookahead for the italic pattern closing string. Its not particularly efficient, but given the scale of DokuWiki's syntax pattern the effect "probably" won't be noticable.
*goes away to think* :)