1.5.1 in Mambo 4.5.2 - CSS conflict?

I have recently installed gallery 1.5.1 in my Mambo sysem. I use 1.5.1 because I'm on a low-end server, so gallery 2 isn't really an option.
That said, I have the following problem.
When I go to the gallery component, there seem to be some strange conflicts. Text in menu's is all of a sudden a different font, is centerd, cell spacing and padding is alterd, etc. This isn't really pretty.
You can find my site at www.sinestra.nl, and the gallery component is installed under www.sinestra.nl/fotos2. I use Mambo 4.5.2 BTW. Thanks in advance!