diff --git a/pym/builder/variables/builder.py b/pym/builder/variables/builder.py
index efb7b0c..6d5b47b 100644
--- a/pym/builder/variables/builder.py
+++ b/pym/builder/variables/builder.py
@@ -473,6 +473,8 @@ class VariableClBuilderNewId(BaseBuildId):
     def check(self, value):
         if not value and self.Get('cl_builder_source_filename'):
             raise VariableError(_("Please specify the id"))
+        if not re.match("^[A-Za-z][A-Za-z0-9/:_-]+$", value):
+            raise VariableError(_("Wrong symbols in build ID"))
         if value in self.Get('cl_builder_storage'):
             raise VariableError(_("Assemble %s already exists")%value)
 
@@ -680,7 +682,7 @@ class VariableClBuilderImageFilename(Variable):
                                       arch)
 
     def get(self):
-        if self.Get('os_root_type') == 'livecd':
+        if self.Get('os_root_type') != 'livecd':
             base_dn = self.Get('cl_builder_base_path')
             build_id = self.Get('cl_builder_id')
             build_id_path = self.Get('cl_builder_id_path')