you can try this: set Online Certificate Check to "OFF" to rectify the issue.
You can set it OFF by doing the steps below:
1. Menu
2. Settings
3. Phone Settings
4. Applications
5. App. Manager
6. Set Online Certificate Check to "OFF"
7. "Software Installation" should also be set to "ALL"
another way is;
1. Menu
2. Settings
3. Phone Settings
4. Data Manager
5. Application Manager
6. Options
7. Settings
8. Set Online Certificate Check to "OFF"
9. "Software Installation" should also be set to "ALL"
After you have done the steps above, clear your phone's web browser's cache:
1. Menu
2. Internet
3. Web
4. Options
5. Clear Privacy Data
6. Cache
After which, turn off and on phone then try to install application again.