Some silicone lubes will bond to some silicones. This seems to be more of an issue the softer the silicone is, so toys like O2 and VixSkin will be more susceptible (makes sense, as the silicone has fewer crosslinks). Quality lubes seem to have less of a problem also, and it is likely that cheaper silicones might have more of a problem.
I have tested quality silicone lube on several quality silicone toys and did not notice a permanent problem, but (a) the toys developed "hives" that lasted for a few hours (was gone the next day) and (b) it's really hard to clean the silicone lube off of the toys, but it can be done. While this is purely subjective, but it seemed that the silicone lube wasn't as "lubey" on silicone toys. I don't use silicone lube on silicone toys anymore - it's just not worth the trouble.