maybe the texture is corrupted? or maybe the texture carries more memory than the default one?
That shouldn't be a problem... King Dedede's PAC files alter slightly in size, yet never had problems with freezing, even when burning discs with the altered files.
By chance, are you using [the latest version of] ASH? And are you using Photoshop? (Photoshop being highly recommended, as it doesn't delete Alpha Layers and all that whutnot.)