Let's see if we can remove the guesswork here.
If you don't have these, kindly get them free from the Market:
- SystemPanel Lite
- Android System Info
Here's my intended procedure:
- Lauch Android System Info, go to the Tasks tab, Menu-> Sort by CPU - Home key
- Launch SystemPanel Lite, click on the three pie charts up top
- Just leave phone idling, with that screen, and keep an eye on Network and CPU
- Maybe give it some time, see if you're seeing anything that just stikes you wrong for lots of CPU use or network traffic
- Long press on Home key, choose Android System Info, and see what process is offending
- Failing that, choose the Logs tab, save logs and look them over for anything unusual
Note that SystemPanel Lite - with a back key - will give back your full list of processes - and you can tap on any of those for LOTs of process details.
If you're suspicious about any app, go to the Android System Info Applications tab and tap it - it will show you every flag that permits an app to do anything of interest (begins with FLAG_).
Report back and I'll help as much as possible.