...Another question for you would be will I notice the noise if I am not cropping 100% ? I mainly use the pictures in scrap book sizes and to be viewed on my monitor.
I think all I can do is point you at Gordon's real-life noise results page
As I am sure you know, the poor sensor noise levels of compact and bridge cameras stems from their use of small sensors. The only way to escape from this is to dip a toe in the DSLR world. Have a look at Gordon's article Should you buy a DSLR or a Compact?
for a wider discussion about the pros and cons. The biggest con with most DSLRs is the cost: not only are they a step up in quality but those big, high IQ sensors need bigger lenses and both sensor and lens costs rise rapidly as size increases.
Shoot me down in flames, if you wish, but there might be a way out of this. Have a look at Gordon's review
of the Olympus E-410 and check out his gallery shots, particularly the indoor ones
. The kit lens received a separate review here
as part of Gordon's E-400 review. The E-410 is one of the smaller DSLRs around and you can currently pick it up with the Zuiko Digital ED 14-42 f3.5-5.6 lens in the USA for around $700. If you do this before the end of the year you also get $100 rebate - see here
where it states "you can get a cash rebate for your old working digital camera – no matter what brand it is". For $600 that is, in my view brilliant value. The downer, of course, is that you need a telephoto zoom (around $260 if you shop around) to allow you to retire your Dx6490 completely. If the budget is tight would it be an option to forego the rebate and retain the Dx6490 for a while until you can buy a telephoto lens?
If this isn't for you then my last thought is that it might be worth choosing a camera that can save your pictures as RAW files as well as JPEGs. That gives you the option of using software on your PC to reduce sensor noise. There is no guarantee that the results would be better but my gut feeling is that they may
be and you would, at the least, gain same creative control over the process.