flash does not connect to server in some computers

hi, i have this thing: there is an app that has been finished (i hope) and it seems to work ok, this flash loads about 1Mb of flash app, then loads some stuff from the server via xml, generated through a script. as i said, it works ok in some computers, but somebody tells me that in other devices, the flash loads fine, but it gets stuck while loading from the server (it wont go further than the splash theat says 'loading contents'). Since is flash, i assume it is computer independent (it is not like the html, where each device may chow it different according to browser and setup; since is flash it will show and load just as the flash would load everywhere else); but as it seems it gets stuck right when loading the xml, after the flash has loaded (the flash loads the xml from the server), what may be causing this? is there any 'flash option' that may be interfering the flash from loading the xml content?

tnx