As far as I can see, something weird has happened to RE matches from about 4.3 Pre 13 onwards. I'm currently using 4.3 Pre 14 on Windows XP with JDK 1.6.0_02.
Suppose I create a document containing just "Hello", select "Regular Expression", and try some searches.
The following searches work: H.*o, H.*, .*o, e+
The following searches fail to match anything: .*, e*, l*
It looks like "*" isn't working properly in some circumstances.
I'm pretty sure this kind of thing used to work, notably things like (.*)