PDF Running Slowly with Kanji in PDF

Hi there,

I just tried importing some Kanji PDF's (a PDF of about 2.2Mb) and the engine seems to be running very slowly. After turning the page, the shadow remains around the spine for close to a second before the page turn "finalises". Sometimes when turning backward, the engine seems to refuse to turn the page at all.

I have tested to see if this is file size with a non-kanji PDF of >3Mb and the same issue doesn't exist.