diff --git a/frappy/modulebase.py b/frappy/modulebase.py
index b0154be..272a22d 100644
--- a/frappy/modulebase.py
+++ b/frappy/modulebase.py
@@ -522,7 +522,9 @@ class Module(HasAccessibles):
                     if validate:
                         value = pobj.datatype(value)
                 except Exception as e:
-                    err = e
+                    # allow to assign an exception to trigger an error_update message
+                    err = value if isinstance(value, Exception) else e
+                    changed = False
                 else:
                     changed = pobj.value != value or pobj.readerror
                     # store the value even in case of error
@@ -655,10 +657,13 @@ class Module(HasAccessibles):
                 self.pollInfo.pending_errors.discard(rfunc.__name__)
         except Exception as e:
             if getattr(e, 'report_error', True):
+                self.log.debug('error in %r', rfunc)
                 name = rfunc.__name__
                 self.pollInfo.pending_errors.add(name)  # trigger o.k. message after error is resolved
                 if isinstance(e, SECoPError):
-                    e.raising_methods.append(name)
+                    if name == 'doPoll':
+                        # otherwise the method is already appended in rfunc
+                        e.raising_methods.append(f'{self.name}.{name}')
                     if e.silent:
                         self.log.debug('%s', e.format(False))
                     else:
@@ -666,7 +671,7 @@ class Module(HasAccessibles):
                     if raise_com_failed and isinstance(e, CommunicationFailedError):
                         raise
                 else:
-                    # not a SECoPError: this is proabably a programming error
+                    # not a SECoPError: this is probably a programming error
                     # we want to log the traceback
                     self.log.error('%s', formatException())