Appearantly it could very well be a (known) wavelab problem, try this:
[Start] -> [Run], type "regedit", open registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}
Doubleclick entry "Upperfilters"
A new window showing values opens. If ASAPI is still installed one of the values is "ASAPI".
If after deinstallation ASAPI and the Upperfilter value is still listed, delete the Upperfilter value manually.
Additional information can be found in the Microsoft knowledge base:
http://support.microsoft.com/support/kb ... 0/0/08.ASP