Apache Solr & Boost module conflict?
Add your search paths to list of pathes boost ignores, either via UI or in the line

RewriteCond %{REQUEST_URI} (^/(admin|cache|misc|modules|sites|system|openid|themes|node/add|comment/reply))|(/(edit|user|user/(login|password|register))$) [OR]


Boost should always be skipped for dynamically generated pages, it can't handle it to well.