I tried to install the SCOM 2007 Reporting Service, it was getting failed with the following errors.
“ Could not verify if current user is in the sysadmin role”

I have spent couple of days to resolve this issue:
Resolutions / workaround:
1.As soon as you install the SQL Server Reporting Service, open the SQL Reporting Services configuration manager and set the proper service account, reporting URL and backup the encryption key. If required Reset Service account and backup.

Open the SQl Reporting URL and check whether your able to open successfully as shown below.

Now start the SCOM 2007 R2 Reporting Service installation, it should solve the above said issue.
Note: This is one of the workaround which I have observed during the SCOM deployments.