Fixed ugly exception caused during items/topic filter
Fixed ugly exception caused during items/topic filter

The exception was caused by blaze if the items inside the data context have changed dynamically but the helpers will be recalled with an now invalid index.

RobNeXX/4minitz,4minitz/4minitz,RobNeXX/4minitz,4minitz/4minitz,4minitz/4minitz,RobNeXX/4minitz