Why is GDB so slow when I type I try to print an invalid symbol?

Question

When I execute in GDB:

p some_nonexistant_variable_name

GDB takes minutes (sometimes) to report that it can't find the the variable in scope.

Additionally when I type:

p some_variable_that_is_in_scope->toString()

it takes forever...sometimes. Not sure why.

I'm using UBuntu 10.04, running GDB through Emacs 23. Any ideas?