After the installation of the last beta version I have the problem that the search in the editor doesn't work anymore as soon as the text to be searched contains special characters like "(" or ".".
See screenshot:
Hi Dirk,
Maybe you should untag "Whole words only"?
I've just tested it in .198 but it' s the same. If I search for VARCHAR2 it works, if for VARCHAR2( not but for VARCHAR2 (100 it works again...
Unchecking "Whole words only" seems to work. Maybe I accidentally activated the option. 
I reproduced this error with the same code snippet and search term. Then after selecting "Regular Expressions" option (i'm a big fan of those; besides being useful, it's nice to be able to practice the skill in TOAD search), exiting TOAD, and restarting, I could not make it happen again. I did notice that the search options stick between sessions.
I can't prove it now, but I am fairly certain I started with no checkmarks and got the error. It seems like search is not quite initialized upon initial entry to updated TOAD, but will work after selecting/deselecting options.
Perhaps it has to do with the fact that the option "Whole words only" is deactivated when "Regular Expression" is activated and remains deactivated even if the option "Regular Expression" is deactivated again.