Web Gallery-Surprising Differences between Safari and Firefox

Question

I discovered some surprising differences using Web Gallery in Safari vs. Firefox:
1. When you first view an album the gallery, the thumbnail photos take quite a bit longer to be visible in Safari than in Firefox.
2. When rolling the mouse over the Subscribe icon in Safari, a message states, "Add this album to iPhoto." In Firefox, the message states, "Subscribe to an RSS feed of this album."
3. When a movie is selected in Safari, you can download it immediately, though the movie is not playable from the Safari page until it fully loads. In Firefox, if you click the download icon before the movie has fully loaded, a message appears that states, "QuickTime is unable to play this movie. Please try again. Then, a window opens asking what to do with the file you are trying to download -- Save it, or Launch QuickTime. If you wait until the movie is fully loaded, it plays within the Firefox page. If, after it's loaded, you leave the page and then go back to that page, the movie won't load again and play within Firefox, but it can be downloaded.
I'm wondering whether these differences in functionality are typical or just occurring on my Mac, so please document your experience here.

Answer 1

Thanks Denes for your reply.
I use HttpWatch tool to measure the loading times. Reports are mostly the same for IE and FF. I can see from the report, there is three times shown error 404 Not Found for the items below.
http://......./images/sRegion-Body.png
http://......./images/sRegion-Bottom.png
http://......./images/sReportBG-Standard.png
The last action which caused 404 error started 2 seconds after the page was asked to refresh. The next action http://......../i/libraries/jquery-ui/1.8.22/ui/i18n/oracle/jquery.ui.datepicker-cs.js started after 38 seconds (hanging in the same place for 36 seconds). Does it mean that the problem is caused by http://......./images/sReportBG-Standard.png action which returns 404 error?
How can I add the missing images?
-Jiri