problem with vba 0.6-0.7.1.....

hi all. ive got a weird problem that for some reason, whenever i load/play a gba rom, every 2-3sec it just gives a slight glitch/freeze for no apparent reason then resumes emulation for another few sec b4 occuring over and over again. It started doing this from vba v0.6-0.7.1 but anythin b4, ie 0.5.1 it works fine and very smooth @ 100% emulation fps
ive tried every possible combo of settings but to no avail..
my specs:
p3 800mhz
32meg tnt2 m64
128meg ram
via apollo 133 chipset
running winxp pro w/dx8.1

thanks for any help u can provide