hmm.....i have been a silent reader for sometime and i think its about time i try to contribute some of the concerns....especially to those who have problem when upgraded to v30....if these are repetitions....i do apologize...

1. i upgraded to v30 through FOTA
2. garmin did not work...showed the black garmin splash screen and then crashed out to home screen
3. my mp3s keeps on getting missing...
4. using bluetooth to stream music to my stereo headset is squeezing all the juice from my battery compared to v21

i found out that you will need to reformat the memory card as I suspect this is the culprit......it could have gotten worse after I upgraded to v30.....

make sure you have full backup of your phone data through pc suite first....just incase

so....i also backup the whole card to my computer.....saw some corrupted files as expected during backup....
hard reset my phone too....just incase....but you may not really need too....i had some junk installations that I want to get rid off...
reformat the card using my computer....took about 10 minutes...i guess it was fixing the corrupted sectors.....
the once done reformat again using the phone utility.....

reinstalled garmin....it works fine now......
transferred back all my data and everything seems to be fine now....

some advice, to those who sometimes or frequently felt that you have missing mp3s from time to time, probably you got the class 2 memory card like me that is not 100% compatible with 5800 that causes corrupted files...here are a few of things that I feel you should avoid:-
a) do not simply remove your card from the phone without properly "ejecting" it from the software first....
b) do not load your card too much....i keep about 2GB of free space.....
c) because of (a), I would suggest that you transfer file using cable to your 5800 and select mass storage rather than using a card reader....i know it will be slow but in my case, i am just fed up of having my files gets corrupted

as of right now......my garmin works, phone IS faster as claimed when upgraded to v30...

will try to see in the next few days if my files still gets corrupted from time to time or not.......and will try the bluetooth again....

hope these advices are useful to some of you out there .......