internal error -3 in R_decompress1

Dear R community,

i ran into a quite cryptic error message while running some non 
interactive calculations. The error message reads:

Error in formals(FilterTSeriesSSA) : internal error -3 in R_decompress1


This FilterTseriesSSA is a function I wrote. Where could such an error 
originate from? What is the best place to start digging for the cause of 
the error? Running the same line of code interactively or using the 
output of dump.frames also does not reproduce the error.


Cheers
jannis