This problem is similar tot eh two-byte japanes sheet name problem
discussed on the gnumeric list:

Rename a sheet to "A,1"
choose Correlation Analysis tool
select a range on the sheet A,1
since the sheet name is not quoted the okay button doesn't become active.

reason:

	static char quote_chr [] =
	{ '=', '<', '>', '(', ')', '+', '-', ' ', '^', '&', '%', ':', '/',
	  '*', '\\', '`', '\'', '´', '\0'};

doesn't include ','

Solution:

we should rewrite sheet_name_quote such that all characters but
alphanumerics cause quoting. (This may also solve the japanese two-byte
problem)