Just because the cable has cat5e printed on it it doesn't mean to say that it'll cope with cat5e limits in every single application or for that matter it'#s actually true cat5e cable
The cable path, materials, and local emc sources can impact on the speed attained.
For gigabit (even indoors) if you're having a problem with cat5E then yes Cat6 or 7 will probably help though even cat6 can be limited to about 30m in certain electronic hostile areas