after upgrading to the dev version from 11 jan 2011, i started to get PHP warning messages re. illegal offset type in common.inc, line 1805 -- only with the new version of views_slideshow.
a diff between the previous version and this one showed that the culprit is this statement in line 201:
drupal_add_css($module_path . '/views_slideshow_controls_text.css', array('type' => 'file'));
- 'type' shouldn't be 'file'; according to the documentation in common.inc, it's either "module" or "theme", defaulting to "module";
- the function in common inc (function drupal_add_css($path = NULL, $type = 'module', $media = 'all', $preprocess = TRUE)) doesn't expect an array at this point, but a string;
not providing this parameter, or providing the string 'module' resolves this problem; no error or warning messages appear.