I use "IO::Select" and/or "LWP" at fastcgi, daemon modules, so if these error occur, these error last unless fcgi/daemon restarts..

Ah hah. Likely, some other module is requiring IO::Select for you, but not always but only sometimes, depending on the kind of request that comes in. So I can only recommend you actually put use IO::Select; in your code, and also use URI; if you use either of them anywhere.