Eseries / Communicators :: Nokia E6 How Can Free Up Memory In C Drive

I am using a Nokia E6, Belle version. I have a simple problem. But the answer to this has not been satisfactory in any forum. My phone memory (C drive) is low, and a warning message keeps popping up. I have done all that I can to free up memory.

1) I have no image, video or any other multimedia stored in the phone memory

2) I am using only one mailbox (active sync - gmail)

3) Only WhatsApp has been installed in the phone memory by default (nobody can install WhatsApp in any other location than the phone memory)

4) Lastly, no other application is installed in my phone memory, other than system files

5)I use a data plan that is always "on"

I want to know what is taking up so much of the phone memory when I have nothing except system files in the C drive?Nokia support give the standard reply -- clean messages, move multimedia from phone memory, etc. But this is illogical since I have no multimedia in C drive. I can't see anything that needs to be moved or cleaned.Also, when I check the memory status, I get at least 300 MB used in the "Others" category of the phone memory. What is this "others" category? I want to access that damn folder and delete everything in it.When I check my phone memory in morning, I have 70 MB free. By noon it comes down to 50 MB. By 7 pm the free memory is less than 5 MB, and then the warnings come.Like I told you, I am using only WhatsApp and Active Sync, is it possible that these two are the culprits? Are they continously downloading something and storing it in my C drive?I request you not to give me the standard "clean your drive" reply since it is not working in my case. Can anybody just tell me what is this "others" folder in C drive that shows up when you long press the drive in the file manager application? How can I free up memory in my C drive? Please, no more standard replies that don't work.