  Low-temperature plasma ejected in solar eruptions can screen active regions
as well as quiet solar areas. Absorption phenomena can be observed in
microwaves as 'negative bursts' and in different spectral domains. We analyze
two very different recent events with such phenomena and present an updated
systematic view of solar events associated with negative bursts. Related
filament eruptions can be normal, without essential changes of shape and
magnetic configuration, and 'anomalous'. The latter are characterized by
disintegration of an eruptive filament and dispersal of its remnants as a cloud
over a large part of solar disk. Such phenomena can be observed as giant
depressions in the He II 304 A line. One of possible scenarios for an anomalous
eruption is proposed in terms of reconnection of filament's internal magnetic
fields with external large-scale coronal surrounding.
