Try taking off the part in red:
Response.Write "<a href=""" & ChkString(rs("M_PHOTO_URL"), "displayimage") & """>" & getCurrentIcon(ChkString(rs("M_PHOTO_URL"), "displayimage") & "|150|150",ChkString(rs("M_NAME"),"display"),"hspace=""2"" vspace=""2""") & "</a><br /><font face=""" & strDefaultFontFace & """ size=""" & strDefaultFontSize & """>" & fLang(strLangPop_Profile00190) & "</font>"
So that it looks like this:
Response.Write "<a href=""" & ChkString(rs("M_PHOTO_URL"), "displayimage") & """>" & getCurrentIcon(ChkString(rs("M_PHOTO_URL"), "displayimage"),ChkString(rs("M_NAME"),"display"),"hspace=""2"" vspace=""2""") & "</a><br /><font face=""" & strDefaultFontFace & """ size=""" & strDefaultFontSize & """>" & fLang(strLangPop_Profile00190) & "</font>"
That removes the part that specifies the dimensions of the image. It should use the images actual demensions now. Just be careful that you don't have users linking to images that are so big they break the page.