I hadnt had any problems with my 510, the users complaining must have got shiny surface beneath, which every other Optical MOUSES can show problems on.
other than this, MX510 is not Lazer technology as you mentioned. these MOUSES have Optical technology.
Intel Core2Quad 2.66Ghz 12MB L2-Cache
4096MB DDR Kingston Hyper-X
XFX 9600GT AlphaDog
Seagate 2 X 320GB SATA2
LG L246WH Flatron 24"