Lucene Search shows no results, but an error in the log file

In the described configuration the Lucene Search does not show any result.
In the Log is an Error entry:

2010-07-20 16:43:06,100 http://myserver:8080/xwiki/bin/view/Main/LuceneSearch?text=subversion&x=0&y=0 ERROR internal.DefaultVelocityEngine - Left side ($searchresults.getHitcount()) of '>' operation has null value at xwiki:Main.LuceneSearch[line 151, column 35]

In xWiki 2.2.2 the Lucene search did pretty well. Because of the MS SQL Server this bug is extreme ugly, actually none of the serach options does work.