[Search in cat] Plugin stopped working in 2.5.1

I found a plug in here
original site (Russian)
http://mywordpress.ru/plugins/search-in-category/
translated to English
http://translate.google.ca/translate?u=http%3A%2F%2Fmywordpress.ru%2Fplugins%2Fsearch-in-category%2F&sl=ru&tl=en&hl=en&ie=UTF-8
that lets you search a specific category, after upgrading from 2.5 to 2.5.1 the search seems to no longer work, any one able to help me get it working in 2.5.1? i posted on the creators blog already