I've been having problems (Undefined property in computed_field_tokens) with using tokens to access computed fields and in preparing to submit this bug report it turned out that the issue only occurs when the computed field is part of a field collection (so apologies if the bug is actually in Field Collection).
In any case, in order to try and figure out where the problem comes from, I created a new site with Drupal 7.18 and enabled the Computed Filed 7.x-1.0-beta1, Token 7.x-1.4 and Devel 7.x-1.3 modules.
I then create a new content type with an integer field, create a new content of this type, use Devel to inspect its tokens and there is no error.
When I add a computed field to the content type and inspect the tokens again, I see the token for the new computed field, and there is no error.
I then enabled Field Collection 7.x-1.0-beta4 (which required Entity API 7.x-1.0-rc3), created a new field collection "items" with fields "field_items_integer" and "field_items_computed", and then if I use Devel to inspect its tokens the following errors occur and I cannot use the computed value:
Notice: Undefined property: stdClass::$field_items_computed in computed_field_tokens() (line 425 of /srv/www/gc/htdocs/sites/all/modules/computed_field/computed_field.module).
Notice: Undefined property: stdClass::$field_items_computed in computed_field_tokens() (line 440 of /srv/www/gc/htdocs/sites/all/modules/computed_field/computed_field.module).
Can this be fixed in Computed Field or should I report it to Field Collection?
Thanks in advance.