Split loop error with perl 5.8

Lars Povlsen has asked for the wisdom of the Perl Monks concerning the following question:

Grrrretings! In a script of mine, I've used

split(/[\s,]+/, $x)
[download]

to split input lines consisting of word lists like

aaa bbb cc
aa, bb, cc

Unfortunately, this now breaks running on RH8.0 (perl 5.8.0), producing a "Split loop" error.

I have tracked the error to be provoked with any regexp containing character classes ([]) (and using it with split).

I am somewhat baffled, but if I am doing something wrong, please let me know...

PS: I have a workaround, but I am more interested in why the split is in err...!