Please help - my N82 realplayer goes blank after 3...

Question

now i know that the N82 may be considered a dated model by todays standards, but bear with me because i finally got one (and a used one at that too). two weeks into owning it and i love it already.
the firmware says:
v31.1.0.16
09.12.08
RM313
i've spent days checking out available add-ons, installing and uninstalling them (also hugely due to the advice i only discovered about installing to the phone memory for better performance). so i've pretty much got it up to the kind of phone i can be proud to carry around.
i face one problem - realplayer goes blank after 3 seconds of playing any video.
i did all these:
- dragged and dropped videos from my pc to phone storage (My Videos)
- copied videos to phone memory (My Videos also)
- converted the videos to mp4, and also 3gp using xilisoft converter before transferring
- tried using Nokia Nseries Video Manager. gave up because it was so user-unfriendly. i could only copy back to pc; i could not find any way to convert and transfer to phone in there
none of these could make realplayer play videos past 3 seconds. i could hear audio though.
the strange thing is realplayer plays when i click on a video in file manager. it does not auto rotate to landscape mode, and does not play more than the file i click on.
can someone help me? sorry i had to post here. i googled for answers, saw a lot of posts from n95 users saying the same thing but didn't see any solution posted. i could not find anything in the boards here either. i would much rather fix this single issue than to perform an update for fear of losing everything i have done in my phone so far.
thanks in advance

Answer 1

Thank you guys for all your solutions. Problem solved on my own (again).
Despite being smartphones, Nokia phones (well, mine anyway) behave erratically when loaded with applications and games, but most expecially with too many themes onboard.
Install one theme too many and you'll start seeing how badly the N82 copes with performing as it did out of the box.
I've had these few nagging issues, which I solved on my own without having to resort to a soft reset or a hard reset or a firmware update or a reformat like everyone suggests without thinking, THANKFULLY.
1. Realplayer doesn't display video in landscape mode
- Bring the number of installed 3rd party themes down to a minimum
- start uninstalling applications, beginning from the most recent one, and check realplayer each time.
2. Multimedia button won't bring up Gallery
- Bring the number of installed 3rd party themes down to a minimum
- Restart phone and see if it does the second time around
- Uninstall the most recent application/s and check again
3. "Help" is not accessible from the menu. It says "Memory full" every time
- Bring the number of installed 3rd party themes down to a minimum
- Start uninstalling applications again, and recheck.
4. Camera recording works fine for 10 seconds, then it stutters every 5 seconds
- If you are using a new memory card like I did, just perform a format from the phone and not the computer before using it. I used it without formatting it so it was my fault.
(but I cannot believe I had to find this solution outside the Nokia boards)
Do I hate my N82? No, I love it.
Do I hate encountering problems on my phone? Of course I do.
It's a great phone, capable of delivering more than other phones if you exploit it like I do, but I wish the developers have the decency to put up a list of common problems and fixes for the phones they roll out, not leave it the hands of discussion board "wizards" and "gurus" to solve your mistakes.