Windows is geared to work with Ver 4.2 (there is a special compat mode for it - only the album part requires a special mode). So I'd say the absence of a compat mode for 5 means it doesn't need one and will work. Programs known not to work (and windows can't give it the special features to fix it) also are listed in compat and it pops up a message saying you have to upgrade. If 5 was released before XP was (and ULead only have info on 6 and up suggesting 5 predates XP) then it's a good bet it will.
Any non faulty program will work out of the box. It is where programmers don't follow MS's rules that compat becomes an issue. EG In 98 the rules may say don't do a certain thing. But if you do it nothing bad happens on 98. But MS often has long term plans where they know it won't work in future (hence the rule).
If they followed the rules it will work on windows for years to come. Programs written for Windows 2 (18 years ago) often still work on XP. XP won't attempt to run Windows 1 programs (20 years old).