requests is not python 2.4 compatible
Can you use httplib2 instead ? http://code.google.com/p/httplib2/

```python
from checks.libs.httplib2 import Http
```
and then adapt your code to its interface.
You'll find an example of check using httplib2 here:
https://github.com/DataDog/dd-agent/blob/master/checks.d/http_check.py

Thanks a lot!