igraph: decompose.graph: Error: protect(): protection stack overflow

I just got this error:

library(igraph)
comp <- decompose.graph(gr)

Error: protect(): protection stack overflow
Error: protect(): protection stack overflow

what can I do?
the digraph is, indeed, large (300,000 vertexes), but there are very
many very small components (which I would rather not discard).

PS. the doc for decompose.graph does not say which mode is the default.

Sam Steingold (http://sds.podval.org/) on Ubuntu 11.10 (oneiric) X 11.0.11004000
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