efke positive paper won't fit 5x7 holders

[enochRoot]

i purchased some efke positive paper to try out in 5x7 sheet size. the paper is 177mm x 127mm (pretty close to 5x7 exactly). the problem is that it won't fit in the holder. the 5x7 sheet film i have is slightly smaller (175mm x 125mm), and fits the holders perfectly. what gives? they aren't 13x18 holders. should the paper be the slightly smaller size that my sheet film is? cutting it down' doesn't seem like something i'd be able to easily do. it's the short width that will not fit. i can get it in there, but the paper is quite buckled and warped.

any help would be appreciated.
thanks!